plus, the new pbs drama "mercy street," described as "gone with the wind" meets "mash," focuses on medics during the civil war.

>> there's this feeling that it's entirely grounded in its time and place, and at the same time it feels modern and urgent and vital. >> woodruff: all that and more on tonight's pbs newshour. >> major funding for the pbs newshour has been provided by: ♪ ♪ ♪ ♪

>> supporting social entrepreneurs and their solutions to the world's most pressing problems-- skollfoundation.org. >> the ford foundation. worldwide. >> this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> woodruff: the first two weeks of 2016 will go down in wall

street history-- for biggest losses to begin a year. stocks plunged again today as oil prices fell below $30 a barrel. the dow jones industrial average lost more than 390 points to close below 15,990. the nasdaq fell 126 points, and the s&p 500 dropped 41. since the year began, the dow and the s&p are down 8%. the nasdaq is off 10%. we'll get a full report and analysis after the news summary. the obama administration has ordered a nationwide pause on issuing new coal leases on federal land. that's while the department of interior reviews whether coal companies are paying enough in royalties to the government-- and what the environmental effects are. roughly 40% of the coal produced in the united states is mined on federal lands. in chicago, protesters

frustrated by police killings made their views known today. dozens of black ministers boycotted an annual martin luther king junior breakfast mayor rahm emanuel hosted this morning. but at the event, emanuel pledged to address their concerns. >> we also have to root out the cancer of police abuse. because the quest for safe and secure neighborhoods and against violence demands trust between the community and the police. and when there is no trust, there is no safety. >> woodruff: there've been charges of a cover-up in the death of teenager laquan mcdonald, who was shot 16 times by a white officer in 2014. video of the shooting was withheld until last november. yesterday, officials released footage of the killing of a car-jacking suspect in 2013. coast guard crews in hawaii

spent this day searching for survivors after 2 u.s. marine helicopters collided and crashed at sea, overnight. they carried 12 people on a night training mission off oahu. an aerial search began before first light and crews spotted a debris field spread across two miles of choppy seas. there's no word on the cause of the crash. the u.n. children's fund, unicef, painted a desperate picture today of starvation in syria. two relief convoys reached the town of madaya this week after a long siege by syrian government forces. u.n. workers found severe malnutrition among children-- and local officials told of 32 people starving to death in the past month. lindsey hilsum of independent television news filed this report. >> reporter: mouadamiya, less than six miles from the center of damascus, hasn't had the same attention as madaya, but maybe it should.

today a mobile clinic was allowed in. the health center is full of people seeking treatment. her 15-year-old son needs to go to hospital in damascus but, despite the urgency, the red crescent and u.n. haven't yet managed to negotiate to get people out. she's getting the telltale signs of malnutrition. her mother pulls back her towelling jacket. "there's no milk for children," she says, "look, her hands are getting thinner." the u.n. says 450,000 syrians are living under siege across the country. mouadamaiya is held by rebels who the syrian government is trying to starve into

submission. >> the regime bombarded the roads into our town, we're under siege, the road's been closed for twenty days now. there's no food or medicine. >> reporter: today the russians dropped humanitarian aid on deir ezzor, a town held by the syrian government and besieged by the islamic state. at the same time russian aircraft continued to drop bombs on rebel-held parts of aleppo, and syrian children continue to live with the fear of hunger and death. >> woodruff: western nations called an emergency meeting of the u.n. security council today, to demand the warring parties in syria end the sieges. police in indonesia now say the suicide attack in jakarta that killed two civilians was indeed funded by the islamic state group. five of the attackers died in the assault yesterday. overnight, anti-terror officers arrested several people just

outside jakarta. it was unclear if they're directly linked to the bombings, but the national police chief promised more arrests. >> ( translated ): for sure, there were people who helped in the attack, including those who facilitated the buying of materials, people who assembled the bombs and so on. they are involved in the attack, so i ordered they be tracked down, all the people involved in the attack including its network, and arrested. >> woodruff: separately, today, indonesian president joko widodo visited the site of the attack and talked to business owners. he said, "everything is back to normal." in somalia, the islamist militant group al-shabab claims that it overran an african union base today, and killed at least 63 kenyan soldiers. it happened in southwestern somalia, near the border with kenya. witnesses confirmed the militants took over the site. kenya's president acknowledged casualties, but gave no numbers.

the u.n. human rights chief warned today that burundi is sliding toward a new ethnic conflict between tutsis and hutus. he accused government security forces of gang rape, torture and mass killings of political opponents. in geneva, a spokesman for the u.n. agency said many of the victims were members of the tutsi minority. >> the suggestion that an ethnic dimension is now starting to emerge, is reinforced by one of the sexually abused women, who said that her abuser told her she was paying the price for being a tutsi. another witness claimed that tutsis were systematically killed, while hutus were spared and the decision to arrest people was also reportedly largely made on an ethnic basis. >> woodruff: burundi suffered 12 years of civil war that finally ended in 2005. but the u.n. says 432 people have been killed in rising violence since april. and, test results confirm a new ebola death in sierra leone.

the news comes one day after the world health organization declared the two-year epidemic in western africa was finally over. officials say the latest victim may have exposed at least 27 other people. still to come on the newshour: dropping oil prices ripple through the global economy; mark shields and david brooks analyze the last g.o.p. debate before iowa; boosting diversity in silicon valley; and, could "mercy street" became the next "downton abbey?" >> woodruff: now, the market plunge that is sweeping across stock exchanges from asia to europe to new york. it has been relentless since the year began, and today was no different. the closing bell on wall street signaled the end to a turbulent

day-- and a tough week-- for markets worldwide. fueling the "sell orders:" another plunge on china's shanghai composite stock index. it's down 18% since the year began, as worries about the chinese economy mount. and, plummeting oil prices are dragging down energy company stocks and the broader market. in washington, white house spokesman josh earnest said u.s. officials are closely monitoring the global sell-off. >> there's no denying that weakness in other markets with whom we do extensive business is going to be a headwind for the u.s. economy. we're mindful of that, particularly as the international economy becomes more integrated and we have to be sensitive to movements that we see in the economies of other countries. >> woodruff: the u.s. market was also hurt by disappointing reports on several major economic indicators. industrial production fell for

a third straight month in december. and, retail sales unexpectedly dropped a tenth of a percent last month, partly because warmer weather hurt winter clothing sales. for a closer look at the dramatic drops in the both stock market and world oil prices, we turn to liz anne sonders, chief investment strategist at charles schwab; and bradley olson, national energy reporter for "the wall street journal." and we welcome both of you to the program. liz anne sonders, what is behind this volatility today in the market? >> many of the same things, actually, that contributed to the volatility we saw last year. you've touched on oil but it's nor broadly what's happen a anything the commodity complex and not just the huge plunge in and of itself but what that says to global growth. of course related to that is china, the weabness, its equity market, economy, currency, tied

into prices. more uncertainty regarding the fed. we got past the uncertainty defining 2015. they got the first rate hike. now it's what are they going to do from here? will they continue to raise interest rates? what will be the justification. a lot of it is unfinished business from 2015, just conspired to occur in a condensed period of time at the beginning of the year which adds to angst of investors. >> woodruff: is this the kind of anxiety that's justified or just gotten out overhand in the last few days? >> it's hard to say. i'd love to know where the correction stops. we do not think this is the beginning of a nasty bear market but could get worse before it gets better. i think investors have been fairly skittish for much of this bull market all along and when you get the bouts of volatility particularly if it's got fairly dire news associated with it, we

really hunker do much more quickly than in the past because i think we really changed the psyche of a generation of investors not only because of the severity of the financial crisis but the fact it came within so years of the bear market that preceded it. i think that explains why we see this sense of urgency and sometimes panic kick in so quickly in this environment. >> woodruff: bradley olson, let's talk about the oil side of this. what is driving this continued drop in oil prices? >> well, there are two main factors at play. the first one is a little tied to what's driving the falling stock markets worldwide and that's china. china's always been the golden goose when it comes to oil markets, particularly with demand. china's about the second largest oil consumer in the world, so whenever there are indications that the chinese economy perhaps isn't going to be as strong as people expected, it cause as great deal of uncertainty when it comes to oil. the second factor is iran. the sanctions are about to be

lifted that were imposed by the united states and the european union, and once the sanctions are up, a lot of people anticipate a significant a amount of oil coming into the market from iran, perhaps this year as much as 500,000 barrels of oil. so the market is already oversupplied, then you dump additional barrels into the market from iran, then problems or questions about demand that would have been able to bring up the price. so there are a lot of indicators that are not positive at this time when it comes to the oil market. >> woodruff: is it expected the countries will continue to pump regardless of how low the price is going? >> that's right. i mean one of the things you see happening when the price goes down is that everybody's trying to make up for the lost revenue. so this is something that's actually happened in the history of oil crashes is that all the producers and companies actually try to pump more oil because they're trying to make up for whatever they have been losing by producing more. in this case, a lot of people

expected the u.s. shale companies and u.s. companies behind a major boon in production in the last few years to slow down and they haven't done that yet. they have been a lot more resilii can't than anybody expected. >> woodruff: liz anne sonders, you used the word "panic" a minute ago. compare this to 2008. >> i don't think this resembles 2008 by any stretch, when you think about the proximate cause of that, it was obviously a easier of the financial system which had global tentacles and the leverage associated with that. what we're seeing is leverage in the financial system is significantly lower than it was back then. what we're seeing has a greater analogy to 1998 than 2008, where you had an environment where you had major currency disruptions, problems in the emerging markets, causing a tremendous amount of volatility and a very severe correction in the u.s. stock market, but it didn't take

the financial system nor the u.s. economy down with it, and i think that's the better analogy than 2008. >> woodruff: so what does that mean? you talked about the psyche of investors and how that's changing, and i think you mentioned millennials. i mean, what is different about the psyche of investors today? >> well, i think we're well past certainly the go-go days to have the late 1990s where there was the cult of equities and everybody was enthusiastic about it, it was a hobby for many. you didn't quite build that back up in 2007. the bubble at that time was more outside the stock market in that it was concentrated in housing. those stocks and homes are the two biggest components of household net worth, so you've gotten the hit to both of those things. so i think what we've established, whether millennials or children of the baby boomsers or the generation after that is not all that different than what we saw come out of the great depression not that this environment is as extreme of that but instituted an era of

deleveraging and i would call ate smarter investor, smarter consumer, they're not spending the wind fall of the lower oil prices. some of it's going to consumption and some to savings and continued debt pay down. that's the kind of psyche change we're seeing. >> woodruff: bradley olson, you mentioned previous oil market crashes. what's the history when something like this happens? how does the price of oil find its bottom before it starts to rise again? >> an adage that exists in the market is low prices cure low prices. what they mean is whenever companies and even countries, you know, don't spend a lot of money, you will see that follow the oil patrick about a year or two years after they stop spending. so what we've seen from the past is when you have underspending for a year or two, that doesn't come to the level that they need to spend to increase production or to bring production to replace all the oil that they've already put out into the market.

whenever you see that happening, that's when the price starts to come back up. already, the level of spending is so low if the past two years, or it's been reduced so much in the past two years, at the it's already worse than at any point in any two-year period in the 1980s. so you already have the ability to compare this downturn and this oil and natural gas crash to the worst to have the periods of the 1980s when it was also very low. so you have to go back to the '70s and the arab oil embargo to find a time when the crash was as bad as it is now. >> woodruff: maybe we all need to turn to the history books in both the markets and the oil situation. bradley olson, liz anne sonders, we thank you both. >> thanks, judy. you.

>> woodruff: the republican presidential candidates returned to the campaign trail today after squaring off last night on a debate stage in south carolina. front runners donald trump and ted cruz dominated the event while the rest of the field continue to try to keep pace. newshour correspondent william brangham reports. >> my friend donald said that he had his lawyers look at this from every which way, and there was no issue there. >> brangham: the "issue" is ted cruz's eligibility to run for the presidency. and "donald" is donald trump, who's been highlighting the fact that cruz was born to an american mother-- but in canada. early on, the issue ignited a testy exchange between the two candidates leading the republican field in iowa, who'd >> i recognize that donald is dismayed that his poll numbers are falling in iowa. but the facts and the law here are really quite clear. under longstanding u.s. law, the child of a u.s. citizen born abroad is a natural-born citizen. >> brangham: trump, in turn, insisted the issue would hang

over his rival's head until it's put to rest. >> if you become the nominee, who the hell knows if you can even serve in office? so you should go out, get a declaratory judgment, let the courts decide. >> brangham: that set the tone for a rough-and-tumble evening, and the candidates got into it again over the texas senator's statements that trump embodies "new york values." >> and listen, there are many, many wonderful, wonderful working men and women in the state of new york. but everyone understands that the values in new york city are socially liberal or pro-abortion or pro-gay marriage, focus around money and the media. >> brangham: trump answered that with a spirited defense of his hometown, harking back to the days after 9/11. >> and we rebuilt downtown manhattan, and everybody in the world watched and everybody in the world loved new york and loved new yorkers. and i have to tell you, that was a very insulting statement that ted made. >> brangham: but it wasn't just

a two-man show. cruz took aim at florida senator marco rubio, for his involvement in a 2013 immigration reform compromise. >> it is also the case that that rubio-schumer amnesty bill, one of the things it did is it expanded barack obama's power to let in syrian refugees. it enabled him-- the president to certify them en masse without mandating meaningful background checks. >> brangham: rubio counter- attacked with a charge that cruz himself has gone back and forth on a number of issues. >> ted cruz, you used to say you supported doubling the number of green cards, now you say that you're against it. you used to support a 500% increase in the number of guest workers, now you say that you're against it. i saw you on the senate floor flip your vote on crop insurance because they told you it would help you in iowa, and last week, we all saw you flip your vote on ethanol in iowa for the same reason. >> brangham: rubio also sought to take down new jersey governor chris christie, a rival for

support of the party's "establishment"-- by painting his record as liberal. >> governor christie has endorsed many of the ideas that barack obama supports, whether it is common core or gun control or the appointment of sonia sotomayor or the donation he made to planned parenthood. >> brangham: christie, in turn, dismissed the jibe as all politics, and no principle. >> two years ago, he called me a conservative reformer that new jersey needed. that was before he was running against me. now that he is, he's changed his tune. >> brangham: but rubio and christie saved their toughest words for the president, hammering away all evening. >> mr. president, we're not against you. we're against your policies. and we are going to kick your rear end out of the white house come this fall. >> brangham: ohio governor john kasich and former florida governor jeb bush also kept most of their fire trained on the white house. and bush emerged today with a high-profile endorsement from south carolina senator lindsey graham, who recently gave up his own presidential bid. the south carolina primary is february 20th.

first, though, the republicans enter the home stretch in iowa and new hampshire. their next debate will be in iowa on january 28th, the thursday before the caucuses. >> woodruff: with that backdrop, it's the perfect time to turn to the analysis of shields and brooks. that's syndicated columnist mark shields, and "new york times" columnist david brooks. welcome, gentlemen. >> thank you, judy. >> woodruff: so, mark, what do you make of that debate last night? >> trump, cruz, no question about it. more than anything else, i got a sense of how dominant donald trump has been in setting the terms of the debate in both parties in 2016. i mean, candidates in both parties, maybe not bernie sanders, but virtually everybody else, is responding or reacting to. we saw marco rubio doing sort of a feisty, aggressive -- not a knock-off donald trump but sort of a vairiation of it.

then ted cruz's first unforced error of the season by his new york, new york. he gave a great opening which he took advantage of. (coughing) >> woodruff: why don't you take a sip of water and let me turn to david. do you have the same impression? >> i'm cross pressured on that. i'm an american citizen born in canada like cruz but i'm a new york citizen and i have new york values. i don't know who to dislike more. but it is a cruz-trump show now. i felt cruz won the debate. on some of the birther stuff, he's more skillful as a debater. but as mark said, trump dominates the discussion, so he's the central figure. cruz may beat him but trump is still the story. if you're looking for a strong liter which apparently the

republican party is, trump is still the main arena, so he can afford to lose a debate and come out ahead. i think thapts where we are now. >> woodruff: where does that lead the race? does it mean it's down to donald trump and ted cruz? >> all the numbers in iowa suggested to two of them, with marco rubio nipping at the heels and ben carson fading in fourth somewhere. as an example of trump, it was a brilliant formulation on the birther issue. he did the birther issue against president obama, you recall. he had his people in hawaii who had uncovered all this information which turned out to be totally bogus, as so much of the charges and allegations always have been, but what he did with cruz on the birther issue was not he was born in calgary, alberta, canada, but he's putting the party at risk by opening himself up to a legal

suit. >> woodruff: if i made him my vice president. >> even if i made him my vice president. so all of a sudden he puts cruz on the defensive of trying to prove a negative. it really is shrewd. at the same time, judy, i do want to give a shoutout, quite bluntly, to jeb bush. he demonstrated character. he's demonstrated character on the issue and the republicans without jeb bush and lindsey graham no longer in the race and with the exception of john kasich, possibly, but they were anti-muslim, bigoted, narrow-minded and intolerant -- >> woodruff: when asked -- jeb bush pointed out, you talking about indonesia, india, the kurds, our friends? i mean, this is an absolutely irrational policy.

but, you know, he stood alone with the possible exception of kasich. >> woodruff: does that mean something for jeb bush? does that translate into something for him? >> jeb bush is part of a large group of people who are a team at half time who like the republican establishment feel they're down 50 points and feel they're going to lose the game. the republican establishment don't feel ted cruz or donald trump can win, they think it can peril the them in congress and they're not doing anything about it. >> woodruff: what could they do? >> i wish we had grey men in suits, but the donor class could do something. the country is filled with congressmen, senators, local committeemen, a lot of whom are in panic, and, so, maybe they should do something about it. maybe they should have a moveon.org type organization and get some rallying which the other side has already done and have a counterweight so they don't send the party into

suicide, and that might involve not now but after new hampshire winnowing the field and donors and other people going and saying we're going to pick rubio. i'm sorry, jeb, you won't be president, christie, you can be secretary of treasury, but we're going to get organized and not go quietly into the night. >> woodruff: go into a smoke-filled room? >> i'm pro conspiracy right now. you think it's that critical? know, i have no confidence in my judgment -- i shouldn't say that on tv. (laughter) >> woodruff: mark and i have confidence in your judgment. >> because i thought trump will fade and i still sort of think he'll fade. >> woodruff: sort of... right now, trump and cruz both are looking pretty good and i don't think either is electable and neither do a lot of republicans, so the question is why do they just sit there and do knotting? >> woodruff: but, mark, again, that raises the question. what about the the others?

there is rubio, christie, jeb bush, john kasich. why are they having so much difficulty rising and getting critical mass? >> i think they're having sleepless nights trying to figure it out, judy. john kasich insists on mentioning in every sentence that he served 18 years in the house of representatives, which is a disqualification in the current climate. if you're spent more than two high school tours in washington, that makes you morally suspect to these primary voters. jeb bush, 75% of republicans said as recently as last june that they could vote for jeb bush, see themselves voting for jeb bush in november. that's down in the same "wall street journal" fb c poll out last night to 42%. for some reason, you know, they're visiting a wrath they feel toward his brother. remember, the tea party was spawned in some degree in reaction to what they felt had

been certainly the breaking with the conservative compact of the bush years on immigration, on spending oen any number of issues. and with the others, christie is running a one-state campaign. i mean, e's running in new hampshire. if he were to do well -- >> woodruff: he has to do well there. >> he has to do well there. rubio -- you know, rubio is everybody's second choice, but he's got to have a victory, and i don't know where that is. >> i'm not sure he's taking the right tack. he's darkened his tone and gone on attack of immigration and the other stuff. to me, you want to be the alternative. if people want the cruz move, they'll vote for ted cruz. >> exactly right. >> woodruff: mark has made this point about other campaigns, when a and b attack each other sometimes c benefits,

but if it's c, d, e, f, g, it's not going to benefit, so they ho have a c. i don't think new hampshire will decide it. we have to go through a lot of states so a lot can happen down the road smvment how somebody needs to take initiative, but it's not going to be ted cruz. >> woodruff: on the democratic side, the hillary clinton camp is feeling anxiety over bernie sanders who's doing better in iowa, has been doing well in new hampshire. we've seen a really interesting back and forth. i mean, her camp going after sanders this week. >> yes, it was kind of good old bernie until he became a threat. as bernie rose in the polls, he became a more formidable adversary but also one menacing adversary. the clinton campaign this week, and in perhaps the stupidest abilitactof the entire year tooe

person who's a character witness, a privileged observer of hillary clinton and can testify about hillary clinton as a human being, a mother, a grandmother, as somebody who's always been there, who's been a force for decency in her life, who's taught and loved her, cheslechelsea clinton, and turnr into a political hack. it was reckless and stupid. they neutralized the advantage and value of chelsea clinton by turning her into an attack dog on a phony charge that bernie sanders, a supporter of single-payer national health insurance, is somehow going to dismantle children's health and medicare. it tells you how nervous, how dumb, what bad judgment there is in that campaign. >> they're worse on the attack and the counterattack. they tend to overreact. if i were hillary clinton, i would think i may lose iowa and

new hampshire, it's possible. i'm more diverse with electorate so don't poison the brand. i think they're too combative, overreacting and making it worse. i understand why they're concerned. there is a gigantic anti-establishment move in both parties, i understand that. but there is little evidence sanders can translate victories in states where there are more minority voters, frankly more conventional and more representative of the country, and she's still sitting pretty in those states and she should just let it be. >> woodruff: you think she should just relax and not worry about losing. >> unless you could counterattack effectively. not something plainly disingenuous. bernie sanders' weak spot is not healthcare for people who need health insurance. >> bernie sanders, whatever else, he's not pretty, he's not a back slapper --

>> his wife would disagree. but he's not a story teller, he's not a cuddly bernie or a well-polished guy. he's absolutely authentic and this attack was synthetic and fab ricated. i would say there is a concern in the clinton campaign. what you have to do is somehow project her as a more likable person. this did not make her a more likele person or candidate. judy, nobody has been nominated in modern era who lost both iowa and new hampshire. >> woodruff: so maybe she shouldn't relax. >> this isn't a normal year. i think momentum could be dangerous, especially how you lose them. if you lose them looking mean-spirited and small-minded, it can't be helpful in nevada. >> i feel the big question is not day to day, it's how deep is disgust in the country, it's a tectonic question.

if the disgust in the country is deeper, we knew it was there and there is a level of anger that's building and events are building and even attacks on cologne, even on the republican side, that could sweep away establishment candidates. >> woodruff: on that note, david brooks and mark shields, thank you both. >> thank you. >> woodruff: silicon valley, the home of the california tech industry, has long been criticized for its lack of diversity. almost two years after major companies, led by google and intel, started to publicize their diversity numbers, the ethnic and gender makeup of the industry's workforce remains almost the same. analysis of employees at the leading tech firms that report such figures reveals: on average, 71% are men;

29% are women; 60% identify as white; 23% asian; 8% latino; and 7% black. so, what exactly is silicon valley doing to improve its diversity? hari sreenivasan takes a look, in the first of two stories. >> raise your hand if you've heard of unconscious bias before. >> sreenivasan: the notion that hidden bias can be methodically stamped out of the workplace has become popular with tech companies across silicon valley. >> by managing unconscious bias, we make better decisions. so, unconscious bias acts as a significant barrier to objective data-driven decision making. >> sreenivasan: that was the message being delivered by joelle emerson, a former sexual harassment litigator who now spends most of her time helping multibillion-dollar startups diversify their workforces. >> we think that if you can get this right early, you're going to much more successfully, more organically grow as an inclusive

company rather than starting when you're so far down the line. if the word is associated with "female," i want you to raise your right hand and say "right." >> sreenivasan: on this day, emerson is conducting a workshop at slack, a $2.8 billion startup just named "company of the year" by inc. magazine. even though his company is still young, slack c.e.o. stewart butterfield is still playing a little catch up. >> we didn't get started in the beginning, right, when this was co-founded by four white men. but it was something that became apparent as a priority to us when we were relatively small, you know, by 30 or 40 people. >> sreenivasan: known for its workplace communication app, slack is regarded as one of the hottest and fastest growing tech startups. >> we are growing incredibly quickly. i mean, we have to do a lot of hiring, which means that there's a lot of positions that need to get filled. every week, there's new people starting; every week, there are open roles. >> sreenivasan: and when there's rapid growth, a natural inclination is to recruit from familiar networks.

senior engineer erica baker says that's at the core of tech's diversity problem. >> there's a lot of focus put on hiring people you know, who you're comfortable with or whatever. a lot of people who get into silicon valley come from backgrounds that are predominantly white, so they hire the people that they know who are predominantly white, and it's cyclical. it will take someone stopping that cycle purposefully to fix it. >> we're going to be hiring a lot of people next year. >> sreenivasan: slack's vice president for people and policy, anne toth, says she's working hard to break that cycle. >> one of the things i'm trying to do here early stage is build the type of tools from the outset that allow us to look at the data in real-time and make adjustments as we go. are we promoting women and people of color at the same rate? are we retaining them at the same rate? are we paying them equitably? are they as engaged as other employees across the board? >> sreenivasan: on the day we

visited, toth, and diversity consultant joelle emerson, were reviewing questions with a group of hiring managers >> where we often go wrong is that we ask questions that produce answers that cannot be objectively evaluated, that almost force us to draw on unconscious biases, on subjectivity, on our own beliefs about the world to evaluate the candidate's answer. >> sreenivasan: the goal: to eliminate any potential bias that might unfairly favor one type of applicant over another. >> what do you do for fun? what do you think of that question? we want to know more about how you are, not just what you do for work. >> we don't want to take the humanity out of this process, but it really isn't relevant to your ability to do work here, what you do for fun. what if what you do for fun is different than what the person who's happens to be interviewing you does for fun? that can be really challenging. what if my answer is "i don't have a whole lot of time for a lot of fun, i have two kids right now that are infants and mostly my spare time is spent taking care of them"?

>> sreenivasan: despite these efforts, slack's diversity numbers are still not dramatically different from the industry. 70% of its employees are white, and 61% are men. an average of major tech but slack c.e.o. stewart butterfield says there are some encouraging trends. >> 41% of employees at slack report to a woman, and 45% of the managers and executives are women. so, that's definitely better than the industry average. >> sreenivasan: for erica baker, an african american engineer, diversity is about race as well as gender. >> right now, it seems like in the industry that diversity is code for "hire more women." that is what diversity has become. and it's not great because the demographics of the industry, usually, it skews to more white women. >> sreenivasan: but baker says she is encouraged by the direction slack is heading. 7% of the company's engineers are african american. compare that with the industry average of 1% to 2%. to change the demographics of an

industry takes time, and one long-term effort involves encouraging more women and people of color to study engineering. many companies are now sponsoring training for high school and college students like this "code camp" hosted by the mobile payment firm, square. >> one of the things i've always loved about programming and computer science is that you can truly build something from scratch. >> sreenivasan: while c.e.o. jack dorsey has not yet publicized square's diversity figures, his executive team includes several women in key roles like c.f.o. and head of engineering. >> at square, we started at the top. so, our board of directors is really diverse; they're driving the company. you move down to our executive team, four out nine of the people who report to jack are c.e.o.-quality women who are running a majority of the company. and so, if we can prioritize from the top, from our board to the executive team, inevitably it will trickle down. >> sreenivasan: vanessa slavich, diversity lead at square, says the company is constantly on the

lookout for tools to expand the pool of prospective employees. >> here we have a job description for our data scientist team. >> sreenivasan: one such tool is textio. the software uses a form of artificial intelligence to detect bias in job descriptions. this is the before copy. on a scale of one-to-100, it scores 47. phrases like "rapidly growing" are regarded as inclusive; "builds relationships," feminine; and words like "relentlessly," masculine. once all the changes are made, the newly revised job description scores a 95. >> we did a small anonymous test with our job descriptions before and after, and they doubled in applications for both men and women. >> sreenivasan: while such efforts can widen the pool of candidates, slack's erica baker says real, lasting change will require a cultural shift in the workplace, taking people beyond their comfort zones. >> people should know that you're going to feel weird about talking about race.

just sit with it and then move past it. but it's going to get uncomfortable. and i think people shy away from talking about those sorts of things because it is uncomfortable. i think that we need to get to the uncomfortable spaces to make good progress. >> sreenivasan: progress will likely take time, especially with older and larger companies. in our next story, we visit google to see how the tech giant is trying to make its culture more inclusive. for the pbs newshour, i'm hari sreenivasan. >> woodruff: part two of hari's look at diversity in silicon valley airs tomorrow, on pbs newshour weekend. >> woodruff: finally tonight, the launch of a new series on pbs: its first original american drama in more than a decade.

jeffrey brown visited the set of "mercy street" in richmond, virginia, and has this preview. >> brown: spring, 1862: the carnage on the war's battlefields goes on, and some of the wounded and dying are brought here to mansion house hospital. >> ah. you must be the new nurse. >> brown: "mercy street" is a dramatized account based on memoirs and letters of doctors and nurses who served at a union facility that also took in a handful of confederate soldiers. the real mansion house, a one- time luxury hotel transformed into an army hospital, was in alexandria, virginia, just south of washington. the series was filmed further

south in petersburg, virginia, as well as richmond, at an old hotel where we visited last summer as shooting was wrapping up. josh radnor plays jedediah foster, a civilian surgeon now caught up in the pain, frustrations and blood of the war. >> it's life and death in a hospital. plus, you throw in the civil war on top of it, and you've got pretty much the most dramatic situation you could ever imagine. there's this feeling that it's entirely grounded in its time and place, and at the same time it feels modern and urgent and vital. it feels like you're walking into this bustling, alive, relatable story with people that you recognize somehow. >> brown: alexandria was the only confederate town occupied by the union for all four years of the war, and much of the drama here involves the interaction of northerners and southerners.

they're very much at war but also at times forced to work side by side... as with two volunteer nurses-- one a staunch new england abolitionist, the other an inexperienced young woman whose life has been upended by occupation. mary elizabeth winstead plays the northerner mary phinney, >> they both feel very passionately about what they believe in, but, as the series goes on, you kind of see the complexities in who they both are, and they find ways to connect even though they have such differing views on such very big, big issues. they see the humanity in one another and are able to work alongside each other. >> brown: the series was created and written by david zabel and

lisa wolfinger-- he, known as the showrunner of longtime hit network hospital drama "e.r."; she, a veteran writer and producer of films and tv programs. >> i thought maybe we can find a new way to tell an old story, and it hit me, that no one has ever really explored the medical side of it. it's "gone with the wind" meets "mash." >> we wanted to find a way to find the drama in the medical. how do we tell the story of medical advances during the civil war but infuse it with drama? and alexandria, virginia, became this great window into a whole bunch of different aspects of the war and all kinds of different characters... it really became much more of a family saga combined with a medical drama combined with a wartime epic. >> brown: one of the most complex and moving stories in "mercy street" is that of samuel diggs, a free black working as a

orderly in the hospital. he'd grown up a servant in the home of a philadelphia doctor and, unbeknownst to the mansion house staff, had learned a great deal about medical practice. as the story unfolds, he gets the chance to do work otherwise denied him in a segregated society. >> i'm talking to a man with a lot of blood on his sleeve. >> yes. >> brown: well earned? >> well earned. this is actually the blood of my love. we just did a scene yesterday where we were operating on her, so, yeah. >> brown: actor mckinley belcher iii told us this role had special meaning for him. >> i think for samuel that how strongly he feels about being a doctor is something that's at the forefront of his mind all the time. people think of the image of a i'm playing a young man who is single-minded-- in many ways a

positive image of a young black man who is career-oriented, has integrity and a sort of quiet strength about him-- it makes me really proud to put that out in the world. and i think in some ways as an artist, i have to be responsible for the images i portray and for the truth i put out in the world. and i'm proud of this one. >> brown: the producers also clearly took some pride in the series' authenticity. a civil war hospital was no setting for the squeamish. amputations were performed numerous times each day without the use of anesthesia >> we're standing in front of a pretty bloody scene, right? at least fake blood. surgeon and medical historian samuel >> brown: surgeon and medical historian dr. stanley burns served as consultant to the series.

>> this is what they call a capitol operating kit. this is what a surgeon used during the war, and there were several of them at each regiment-- or should i say, one at each regiment and several for each brigade. and these are the instruments they used, and we show them in scenes. and so, this is a capitol amputation saw. >> brown: how do you do an amputation? >> they actually took the saw around the arm and then, in one fell swoop, cut it off. the whole amputation. if the surgeons were slow, it would take five minutes, but an good, experienced surgeon could do it in two or three minutes. >> pbs was such a natural home for it, and i think in many ways we designed it for pbs. >> if we tried to tell the story in a lot of other places, there would be a lot more pressure to stray from the facts, from the history. >> brown: the six-part mini- series "mercy street" premieres sunday night. from richmond, virginia, i'm

jeffrey brown for the pbs newshour. >> woodruff: you can stream the first episode of mercy street online now, and the broadcast premiere is sunday on most pbs stations. >> woodruff: now we turn to a newshour shares: something that caught our eye that we thought might be of interest to you. the new york public library recently made available its collection of more than 180,000 images in high resolution to the public. it's a treasure trove reaching back centuries, all accessible with the click of a mouse. the earliest images date back to the 11th century-- ornately decorated persian manuscripts.

from the book of kings. then, a view of the world through the eyes of 18th century mapmakers. scenes of devastation from san francisco's earthquake to chicago's great fire. and a look america's past time played by the game's all-time greats and some serious fans. all of these images and more can found at: www.publicdomain.nypl.org. and on the newshour online right now, it turns out we share more than just fun times with our friends. a new study of chimpanzees shows that being social helps diversify the bacteria in primates' bodies, boosting resistance to infection. in other words, friends keep us healthy. all that and more is on our web site, www.pbs.org/newshour. later tonight on "washington week," why political rhetoric is getting more personal and divisive on the 2016 campaign trail. plus a deep dive into president obama's final state of the union address-- was it about his legacy or the race to succeed him? that's tonight on "washington

week." on pbs newshour weekend saturday, a program in brooklyn, new york, aims to reduce the number of outstanding arrest warrants for low level crimes. >> reporter: on a saturday morning, a crowd waits outside the mount lebanon baptist church in brooklyn, new york. hundreds more pack the sanctuary inside. they're seeking forgiveness-- not from a higher power-- but from new york city's criminal justice system. the event is called "begin again." >> i'm here to clear up a past warrant that i had for trespassing. >> there's nothing worse than walking around the city and having a cloud hanging over your head. >> reporter: brooklyn district attorney kenneth thompson started "begin again" last year. >> warrants never go away. so, when people apply for jobs, they come up in background checks. it could affect someone's application for citizenship. it could affect someone's ability to get housing. so, there are real consequences to outstanding warrants.

>> woodruff: that's this weekend. and tonight on "charlie rose the week:" actor sean penn defends his controversial interview with the drug cartel boss joaquin "el chapo" guzman. >> i had only thought this is somebody upon whose interview could i begin a conversation about the policy of the war on drugs. that was my simple idea. >> you wanted to have a conversation about the policy of a war on drugs. >> that's right. >> woodruff: more of that tonight on "charlie rose" the week. >> woodruff: and we'll be back, right here, on monday, with a wrap up of the sunday night democratic debate, and more on politics monday. that's the newshour for tonight. i'm judy woodruff. have a great weekend. thank you and good night. >> major funding for the pbs newshour has been provided by:

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