later on next week. >> enjoy the rainy night ahead of us. see you back here at 6:00. >> good night, folks. on our broadcast tonight, touchdown, an amazing first for mankind. a spacecraft has landed on a comet in a mission ten years in the making. could help solve some of life's biggest mysteries. also, clearing the air down here. a surprise announcement of a history-making deal between the u.s. and china. high drama at the newly opened world trade center, a scaffolding faile, workers are trapped as it all played out on live television high above manhattan. and are we witnessing the end of black friday? the news that could be a relief to all those who've had enough. "nightly news" begins now. good evening. and we begin tonight beyond the wild blue yonder.

the news today that reminded americans and people all over the world what it feels like to dream and explore and what can happen when science and brain power and engineering combine to take us places far away. after traveling through space for ten years and doing five laps around the sun, a small spacecraft has landed on a comet and both are now hurtling through space at 40,000 miles an hour, traveling somewhere between mars and jupiter. think of it this way, tonight as we come on the air there are american footprints on the moon, a rover driving across the surface of mars, now a spacecraft the size of a washing machine hanging onto a comet for dear life. we begin tonight with nbc's katy tur at the european space agency headquarters in germany. >> reporter: these are pictures from 300 million miles away of something we've never seen this close before, the surface of a

comet. the mission rosetta journey began a decade ago, today success. from mission control in germany to viewing parties across america scientists and space watchers were overjoyed. >> i feel being part of a history proud. >> reporter: and in some cases overwhelmed. rosetta chased comet 67p for 4 billion miles just recently getting close enough to take a landing site and even a selfie. but touching down was anything but easy. essentially it's like dropping a penny into the mouth of an open bottle from a really great height. except this was infinitely more complex. the comet is relatively small, wider than the island of manhattan, it has a rough surface covered in cliffs and craters, low gravity and is constantly spinning. >> and i think it was bold.

it took a certain amount of ambition, shall we say, to even attempt to do this. >> reporter: despite the initial good news, tonight confusion about whether the washing machine size lander managed to stay put on the comet's icy surface. still, scientists did collect some data, and that could help solve one of life's biggest mysteries. how did we get here? >> a comet was formed before earth was. and it brings an enormous amount of water with it. now, we are a water planet. where did our water come from? and one of the ideas is indeed a lot of the water came from outer space through comets and meteorites. >> reporter: mankind has marvelled at comets for centuries. they are the stuff of legend. today they became a destination. and we all got to go along for the ride. katy tur, nbc news, germany. back down here, those concerned about climate change are calling this the breakthrough they've been waiting for, a deal brokered between the u.s. and china to

greatly reduce carbon emissions. though critics are already questioning whether china got the better end of this deal. we get our report tonight from our chief environmental affairs correspondent anne thompson. >> reporter: china's pollution problem is plain to see. obscuring tourist snapshots, forcing marathoners to wear a mask, even the police. the government tried to clear the smog for this week's world leaders meeting by closing factories and banning cars as it did for the 2008 olympics. both had limited success. >> the air itself is just plain thick. the worst it's been here in days. >> reporter: now after years of dragging its feet, china is pledging to reduce pollution by taking action on climate change with the u.s. the u.s. and china, the world's biggest economies are also the world's biggest carbon emitters. >> we have a special responsibility to lead the global effort against climate change. >> reporter: the u.s. promises to cut carbon emissions at least

26% by 2025, doubling its pace. china promises to cap its emissions around 2030 or earlier and bump up its renewable and nuclear energy use to 20%. >> it gives us a fighting chance of heading off the worst impacts of climate change if other countries around the world now join them. >> reporter: for china it means kicking its coal habit. coal accounts for 70% of china's energy. and it's on track to build a new coal plant every ten days for the next decade. but with 1.3 billion customers, china could change the renewable energy landscape. >> this is going to help reduce the costs of renewable energy for all users around the world. >> reporter: here at home republicans are already putting up roadblocks if congressional action is needed. >> the agreement requires the chinese to do nothing at all for 16 years while these carbon emission regulations are creating havoc in my state and other states.

>> reporter: now already the president has acted on his own doubling the vehicle fuel efficiency standards by 2025 and directing the epa to set limits on carbon emissions from power plants. a pew research poll taken after the election shows that 64% of americans support stricter emission limits on those power plants. brian. >> anne thompson on the big environmental story today. anne, thanks as always. tonight, our friends at the weather channel are referring to what's happening right now across the country from north to south, east to west as the arctic outbreak. and it's true. records are falling, and it's really cold out there. nbc's janet shamlian is live for us in denver where it's been a hundred years since it was this cold this early. hey, janet, good evening. >> reporter: brian, good evening to you. that's right, the mile high city's on track to shatter a record that was set in 1916. it has not gotten above 6 degrees, here today it's currently 2 degrees. and this crush of cold is now pushing south and east.

>> i-70 is really -- >> reporter: denver under siege from heavy snow and bone chilling cold. truckers pulling out chains to ready their rigs, some not quite prepared for the deep freeze. >> slick. really slick. >> reporter: that familiar scrape, not usually this soon. >> this is beautiful colorado. >> reporter: from the air an oversized blanket of white. at majestic mt. rushmore, a time lapse look at the mounting snow. steam rising from the icy platte river, casper the coldest at minus 26 degrees. the warnings are now widespread. >> windchills are just brutal outside. >> arctic blast is bearing down. >> we're running some 23 to 24 degrees below average -- >> reporter: in 24 hours the temperatures dropped from the 80s to the 40s in brownsville, texas. in jackson, mississippi from 79 degrees to 45. and in charleston, west virginia, 75 down to 41, a 34-degree difference.

in the pacific northwest, 60-mile-an-hour wind left 60,000 powerless in seattle. crews battled gusts as they try to repair the lines. in oregon trees blocked roads and crashed into homes. as this system pushes east, fog blanketed big cities there today, boston skyline all but disappeared, only the tallest buildings peaking from the clouds and this view from the statue of liberty's torch. what stands out about this storm is its projected longevity. denver and other locations could stay unusually cold for the middle of next week and longer. brian? >> janet shamlian in 2-degree denver, colorado tonight. janet, thanks. let's head to a developing story out of the pacific northwest. we're hearing for the first time the 911 calls for help as a student opened fire inside a high school in washington state last month providing new insight into how these tragic events

played out that day. our reports to hally jack sorn. >> one of the calls from a teacher, meghan silver berger, described by some as a hero for running toward the 15-year-old gunman before he killed himself. >> i need help, i need help one right here. i'm standing out here right now sits next to hill. i need help now. black pants, black shoes, black jacket. >> four other high schoolers were killed. 14-year-old nate hatch who survived was released from the hospital last week. >> thanks. some scary moments late today as the ground shook and shook hard in parts of kansas and oklahoma. 40 quake "a magnitude 2.5 or

above have hit this general area over the past week. today's was by far and away the largest. many others watched on live television as a scaffolding failed high above the city streets on the tallest building of the new world city trade center tower. to the rescue came the new york city's fire department of special forces. 6 our report tonight from nbc's stephanie gosk. >> reporter: the tallest building in the country, 68 floors up and one side of the scaffolding gave way. two window washers left dangling. both experienced workers seen earlier in the day in pictures posted on social media. at 12:42 the call came in. more than 100 new york city firefighters responded. the department tweeted this photo from inside, an up close look at the terrifying angle of the scaffolding.

the first priority was securing the two workers. >> they dropped rope down to additional secure the members that were the workers on the scaffold. >> reporter: then rescuers had a choice, try to raise the scaffolding to the roof or cut through the thick glass with a diamond edge saw. they chose, they say, the safest option. but not an easy one. >> worried about everybody below more importantly. the guys up there secure not going anywhere. >> they're going to take worker number one into the building. >> reporter: they brought them inside one at a time. >> okay. we have a successful mission. >> reporter: both were taken to local hospitals with minor hypothermia. lieutenant bill ryan and his company know this address well. they were one of the first teams called to the twin towers on september 11th. do you think about that when your radio goes off -- >> it's a run. it gets you kicking. we know the location. the rest is business. do what's supposed to be done at that point and talk about it later. >> reporter: after an afternoon that put the city on edge, the day ended with a rescue new yorkers are proud to call a success. >> isn't that something to see? >> reporter: stephanie gosk, nbc news, new york.

a disturbing piece of video making the rounds on the web and elsewhere today. it shows three u.s. navy sailors from the guided missile destroyer "uss ross" which is docked in istanbul right now. the americans are dressed in civilian clothes and surrounded quickly by about a dozen activists calling them killers, shouting for all of them to leave turkey. they throw things at the sailors. at one point they put a bag over their heads. the americans do not retaliate. they do not fight back. they are then chased as they try to get away peacefully. a member of our team who lives there cautions that these were apparently the actions of a fringe group done for the benefit of cameras. and turkey, an american ally, is generally hospitable to westerners. we are learning more tonight about how the pilot of that virgin galactic spaceship managed to survive the explosion that killed his co-pilot. peter siebold told the ntsb he was thrown clear from the aircraft still in his seat. his parachute only deployed

after he unbuckled from his seat during the fall. he also told the ntsb he did not know his co-pilot had unlocked the braking system early. alsbury was killed in the explosion and crash. still ahead tonight, it could be the end of black friday as we know it. could it be? will the announcement from a giant in retailing change retailing this coming season? also, crowded skies. the alarming report today about an increasing number of close calls in the air.

we are back with a story here tonight that could spell the end of what has become black friday. but before you think about leaving your thanksgiving table,

getting in line, braving the stampede, you might find deals just as good or better right now. our report tonight from nbc's tom costello. >> reporter: the leaves haven't even all come down yet, but already at your local store the holiday shopping season is here. >> i love a good deal. deals make you spend money. and that's how they get you. >> reporter: but is it a deal? consumer financial website nerd wallet has found very often those black friday prices aren't so special. example, the listed upcoming black friday sales price for a north face jacket at sports authority, $99. but it sold for that just last week. a slow cooker at sears is black friday priced $19.99, the same price as last thursday. and the 50-inch rca television at k-mart, black friday priced $399, same as september 28. >> retailers are banking on the fact we just don't have time to be tracking prices month by month, week by week. we're busy. especially around the holidays. >> reporter: black friday itself is turning into it's own season.

target already offering black friday deals online. the real deals start the sunday before thanksgiving. walmart plans five days of sales starting on thanksgiving. many more stores offering deals all month. cnbc's courtney reagan covers retail. >> on average for most retailers the holiday season, november to december, represents anywhere from 10% to 30% of their total sales for the year. >> reporter: so the best days for bargains? a new study by adobe finds the largest single day price drop is expected sunday to monday before thanksgiving. but the entire thanksgiving week most items will be discounted 20%. the best online deals expected on thanksgiving day itself average discount 24%. >> i'm a little sick and tired of getting into the last-minute rush, you know? >> reporter: again this season predictions are for a strong holiday sales as retailers bet that by extending black friday consumers can be enticed to spend even more. tom costello, nbc news, bethesda, maryland. we are back in just a moment

with a troubling sign of our times, what most americans feel has gotten wildly out of control.

every day is a new opportunity to help make life better right here in san francisco. whether it's helping local businesses like the fruitguys grow and prosper, supporting nonprofits like juma ventures as they fulfill their mission

or helping neighborhoods like the tenderloin become vibrant communities. if there's a way to help the people of san francisco thrive and succeed, we'll find it. that's the power of local connections. that's bank of america. let's hear that music. we have a senate race to call. in alaska, eight days after the election we can now report the republican dan sullivan is the apparent winner of the u.s. senate seat. the associated press has declared him the winner flat out. that would be a net gain for the gop, another one. he defeats the democratic incumbent mark begich. sullivan is a marine corps reservist, former assistant secretary of state under president george w. bush. marge roukema has died. as a gop congresswoman from new jersey, she came in with the reagan wave in 1980 and served 11 terms. she rose to become the longest serving woman in the house.

former teacher she ran for office initially to deal with the loss of her teenage son to leukemia. she was a moderate who worked with president clinton to pass the family medical leave act. split with her party on guns and abortion. marge roukema was 85 years old. the american people feel they have lost control of their personal information. the latest pew survey shows over 90% don't trust companies with their data. 80% express concern about the government monitoring their communications. put another way the numbers show the people feel their right to privacy is fading quickly and there's nothing being done to stop it. and somewhat related, drone sightings near aircraft especially are now almost a daily event across the u.s. sometimes several times a day. as one veteran commercial pilot put it, so far we've just been lucky that an unauthorized drone hasn't collided with an aircraft. when we come back here tonight, making a difference. 60 patients, one doctor. those are the odds one american is up against in the fight against ebola.

it was just yesterday the u.s. was declared ebola free, but it's so important to remember the mission, the crisis that goes on in west africa where the death toll has now topped 5,000 according to the world health organization. sierra leone in recent weeks has seen a sharp spike in cases. and that's where one brave doctor from boston medical center is making a difference. we get her story tonight from our national correspondent kate snow. >> reporter: at her home in boston, dr. naheed bedlia knew exactly what to pack for her second trip to sierra leone in four months. this time with partners in help. what's harder is being mentally prepared to see so much suffering, patients waiting for treatment, a man who just lost a family member. >> i think that i wasn't ready

to walk in an environment to see so many people die. >> reporter: 10-year-old mark is one of many orphans in port loco where she is headed. >> you walk in and you're covered head to toe in personal protective equipment, and all that's really showing is your eyes. and you have a lot of kids there who have lost their entire families and they are wandering alone, you know. in those ebola treatment units. what do you do? simply bending down and touching them on the shoulder or petting them on the head and looking at them in the eye was enough to take the fear away. that it's not -- it clearly is not nearly enough. it feels good to be back on site and be able to help out. >> reporter: after a 12-hour day in sierra leone we caught up is dr. bedelia on skype. at one facility she visited there are 60 patients and just one doctor. >> you know, you're seeing actually wonderful nurses and they're local nurses committed to the cause.

but there aren't enough. there aren't enough doctors, there aren't enough nurses. >> reporter: so often she says she sees patients helping other patients. she records those moments in her journal. >> inside this ward an entire microcosm of humanity was expressed and almost all of it was kindness, selflessness. i think that anyone who has the time and ability to do so should volunteer. this is our time. it's a call to action for us. for our generation. >> reporter: she wants other americans to know what a rewarding experience it is to be there. kate snow, nbc news, boston. as we salute those who care enough to go over there and make a difference, that's our broadcast on a wednesday night. thank you for being here with us. i'm brian williams. we of course hope to see you right back here tomorrow evening. good night.

right now at 6:00, inappropriate gifts. some san jose police officers under fire for taking gifts from the 49ers. the accusations go all the way to the police chief. good evening and thanks for being with us. i'm raj mathai. >> i'm jessica aguirre. only on nbc bay area, too friendly off the field? under discreetny for freebies top brass got from the tran 49ers, the sjpd could be facing a new investigation tonight. one that might lead straight to the top. robert handa joins us live outside the department with more on the focus that's now being

put on san jose's police chief. >> reporter: that's right. with all the attention on the issue as well as assistant chief eddie garcia, police chief larry eskaviel has never been accused or acknowledged he did, now. the 49ers conduct law enforcement appreciation days but the gift ordinance prevent most san jose fishes from accepting gifts worth more than $50, and prohibits professional sporting events. the assistant chief and deputy chief are being investigated by internal affairs for accepting 49er tickets. now nbc bay area has learned police chief larry escovel accepted the gifts when he attended the appreciation game at candlestick park on august 8th last year with garcia. he filled out the gift disclosure paperwork and reimbursed the 49ers but not until this year. >> this was solely on his part. this was something he realized, i made a mistake, i'm going