on the broadcast tonight, a tipping point. is it possible what's happening right now in the worst place in the world is finally going to get the world's attention and action? a deadly quake in italy. and we're on the scene there tonight as the toll could rise. is it safe to eat? radiation from japan is showing up in tuna caught in california. tonight, should american consumers be concerned? over the top. donald trump doubles down as an obama birther raising problems for romney as trump raises money for the candidate. and measuring up. a major concern for women getting shorter as they get older. tonight, staying strong and standing tall. nbc "nightly news" begins now. captions paid for by nbc-universal television

good evening. as one middle east expert put it, there's two ways the u.s. and the rest of the world can look at this situation in syria. boots on the ground or head in the sand. but what's happening in syria right now is making it harder for anyone to look away. it's been going on for 14 months now. it's close to dissolving into all out civil war. a dictator finds himself under attack from an uprising, and he shows every willingness to try to crush it. the latest massacre has led a prominent diplomat, a former secretary-general of the u.n. to say, we are right now at a tipping point. and he means the rest of the world. it's where we begin tonight with our chief foreign correspondent richard engel. richard, good evening. >> reporter: good evening, brian. even people here in the middle east were growing numb to the violence in syria. but the horror of last friday's massacre has shocked people around the world into action.

action that many syrians say is long overdue. a rare demonstration in bashar al assad's stronghold, damascus. protesters emboldened by syria's growing isolation. nearby the syrian president, now an international pariah, met with the u.s. peace envoy kofi annan. >> we are at the tipping point. the syrian people do not want their future to be one of bloodshed and division. yet the killings continue. >> but syria is threatening its same old lines. it says it wants a cease-fire and blames terrorists for the violence. including the mass kerr in ho huh la that the u.n. now says was worse with than imagined. at least 108 were killed, including 34 women and 49

children. >> the majority are a result of house-to-house summary executions. armed men going into houses, killing men, women and children inside. >> reporter: the u.n. says a shadowy government-backed militia called the shabiha committed the murder. analysts say assad could stop them if he wanted. after months of threats, the united states today ordered syria's top diplomat expelled. >> he is no longer welcome in the united states. >> reporter: and germany, britain, france, spain, italy, the netherlands, canada, bulgaria and australia, all told syrian diplomats to get out. >> this is the most effective way we've got of sending a message of revulsion at what has happened in syria. >> reporter: but as the new video shows, assad isn't getting the message. and syrian forces still vastly outgun the opposition. and today, brian, the state department accused iran of

aiding and abetting the shabiha, the pro-assad militia. activists say the shabiha is trained by iran and uses the same tactics that iran employed to crush its own rebellion. brian? >> richard engel starting us off tonight. richard, thanks. and now to the crisis in northern italy, where a deadly 5.8 earthquake shook the region this morning. the epicenter was just northwest of bologna. the same area where an even stronger quake killed people just over a week ago. and once again, our own jim maceda is there. >> reporter: brian, i'm a few miles from the epicenter of the 5.8 tremor which hit this area earlier this morning, damaging or destroying a number of buildings, like this old apartment complex behind me. at least 15 were killed along the path of destruction. more than 200 wounded. and still seven people are missing, while rescuers continue to sift through the rubble. people here were just getting

over a previous quake, which struck nine days ago with the same intensity and epicenter. thousands were displaced then. some are still in tents. they were shrieking with fear, in fact, running for their lives this morning when that second quake struck. in an area known more for it's parmesan cheese than its seismic activity. but the tents tonight are out again, thousands are facing sleepless nights while few here really believe the italian government -- which pledged to do everything it could to bring their leaves back to normal 37. brian? >> all right. jim maceda in northern italy for us tonight. thanks. now to presidential politics. it's a big day for the romney campaign. it looks like the candidate will pick up enough delegates tonight in the texas primary to win the republican nomination officially. but his big money supporter, donald trump, is grabbing a lot of headlines, raising questions all over again about an issue that was long ago settled,

regarding president obama's birth place. and that could raise some problems for romney appearing with trump tonight. our report from nbc's peter alexander. >> reporter: after a bruising primary campaign, tonight mitt romney makes it official. gathering enough delegates to ensure he'll win his party's nomination. and again today, hammering president obama for his handling of the economy. >> median incomes in america have dropped by 10% in the last four years. and so this president is looking for someone to blame. >> reporter: but the romney campaign's message was trumped by the outspoken tv personality, donald trump himself, who again fanned the flames of the so-called birther movement on cnbc, questioning whether the president is a u.s. citizen. a claim that's been repeatedly discredited. >> i don't consider myself birther or not birther, but there are some major questions here, and the press doesn't want to cover it. >> reporter: trump also tweeted, barack obama is practically begging mitt romney to disavow the place of birth movement. he's afraid of it, and for good reason. for romney, who arrived in las vegas this afternoon, with

trump's personal jet over his shoulder, the timing is awkward at the least. the two men are scheduled to appear together at a private fund-raiser tonight. >> thank you, donald. >> reporter: romney, who courted trump before getting his endorsement, is soliciting supporters withage offer to dine with the donald. on monday night he said he didn't agree with everything his supporters say. >> but i need to get 51% or more, and i'm appreciative to have the help of a lot of good people. >> reporter: the obama campaign lashed out with this new web video, attacking romney for failing to condemn extreme voices in his party, like john mccain did four years ago. >> i have read about him. he's an arab? >> no, ma'am, no, ma'am. he's a decent family man, citizen, that i just happen to have disagreements with. >> reporter: and brian, don't forget, it was more than a year ago -- last april, to be exact -- that president obama released his long form birth certificate from hawaii, in part due to pressure from trump himself, who at the time said he was honored for his role in the

release. now romney finds himself having to answer questions about why he hasn't been more outspoken on this issue. his campaign releasing a statement this afternoon, insisting romney has repeatedly said he believes the president was born in the united states. >> peter alexander in our d.c. newsroom. thanks. this was day 26 of the john edwards campaign corruption trial. again today no verdict. nbc's lisa myers who's in greensboro, north carolina covering the trial for us reports tonight that the jurors have signalled they may not even be close to a verdict, informing the judge of upcoming scheduling conflicts in the next two weeks. today the judge urged the jurors to refocus their attention on their deliberations, warned them not to talk in small groups outside the jury room. it's become a kind of grim marker of the arrival of the summer season in the city of chicago. the murder rate skyrockets. just two weeks ago, chicago was

at the center of the world stage as leaders from nato countries gathered there. this weekend the killings in the cities south and west side neighborhoods ramped up again. our report tonight nbc's from kevin tibbles. >> reporter: another hot, deadly, holiday weekend in chicago. 10 people killed, 42 wounded. 33-year-old malcolm dowdy, a coast guard veteran, killed in a drive by shooting leaving a memorial day party. >> you had nato here and all that security and everything. drill, drill, ten point -- but my son couldn't go to a party. >> reporter: today chicago's police chief charged to protect a town where the number of murders is up 58% this year, says cops need to get ahead of the violence. >> what's really different here is going to be the reliance on the beat officer, putting the resources in their hands. >> reporter: the city's mayor says young people need an alternative to gangs and violence. >> making sure the economic

opportunity does not exist at a liquor store alone, or a drug trade. >> so many young black men are dying, and it seems that no one cares. >> reporter: pastor corey brooks has dedicated himself to saving youth on the south side. but there is more work to do. long time residents note the killings seem to come with the warm weather. and worry another hot summer of violence may be on the way. >> you have a proliferation of guns, you have economic disaster, you have educational issues, social and spiritual issues. and you put all of that in one place, and it's a powder keg ready to explode. >> reporter: and that place is right here? >> it's right here in the innercity of chicago. >> reporter: seeking ways to diffuse the violence before more lives are lost. kevin tibbles, nbc news, chicago. this next item made a lot of u.s. consumers sit up and take notice today. bluefin tuna caught off the california coast have been found to contain elevated levels of radioactive matter dating back

to the japanese earthquake and tsunami that led to that nuclear accident at the fukushima power plant. our report tonight from nbc's miguel almaguer. >> reporter: today at the san pedro fish market in southern california, don inspects the catch of the day, and stressed his fish are safe to eat. >> the word radiation creates fear in people. >> reporter: the 15 bluefin tuna caught and tested off california's coast last summer, showed low levels of radiation, but still ten times higher than normal. scientists say it's the first time a fast moving migrating fish has been shown to carry radioactivity from japanese waters. >> we almost didn't believe it, to tell you the truth. >> reporter: dr. nicholas fisher, professor of marine sciences, co-authored the study. >> every single fish was significantly contaminated with two radioisotopes of cesium. these are common waste products from nuclear accidents. >> reporter: the research shows the bluefin tuna that spawn and

feed in the waters near the fukushima daiichi nuclear power plant, migrated some 6,000 miles just a few months after the disaster. the fish are contaminated, they are considered far lower than what's dangerous 37. today the fda said they'll continue to monitor radiation levels in fish, and no public health concern has been detected. >> i don't think i'll change the way that i eat, not at the moment. >> it's definitely made me alter just a little bit, not eat quite so much. >> look at the tuna jumping right there. >> reporter: massive in size, up to ten feet and weighing more than 1,000 pounds, pacific bluefin tuna is a delicacy, often eaten as sushi around the world. scientists say the real test on how radiation affects migrating fish will come this summer. they will look at fish that have spent more time in contaminated waters and could have higher levels of pollution. >> that is a distinct

possibility. today we don't know the answer. >> reporter: japanese officials will conduct more testing in their waters. this as researchers here do the same. miguel almaguer, nbc news, san pedro, california. still ahead on a tuesday night, you're not just getting older, chances are, you are getting shorter as well. dr. nancy snyderman explains when it's something to worry about, when women shrink with age, and what can be done to prevent it. and later, a remarkable scene at the white house today. highest honors for some living legends.

back now with some important advice for women, who are concerned about getting shorter as they get older. a couple things here. height loss has been a constant for aging women. it can be a sign other health risks, and we now know there are things that can be done to prevent it. here is our chief medical editor, dr. nancy snyderman. >> reporter: 60-year-old

carmella got the message early in life and has been a long time believer in strength training. >> the core is the heart of stability. and from there you're able to then strengthen and improve on your balance, on your flexibility, even on your muscle toning. >> reporter: most women over 40 don't know what carmella knows and they pay the price. it's common for a woman to lose two inches by the age of 70 and 3 inches by the age of 80. due to weak muscles and the flattening of disks in the vertebral columns. >> most of the height loss that we see in women is preventable, if we start early. >> reporter: now, carmella is teaching other women what has kept her long, lean and powerful. it's all about building muscles and keeping them strong. the women in carmella's class are clearly seeing and feeling the benefits. >> i know i'm walking taller. >> reporter: at 74, loretta is a

believer. >> i want to stay strong. my mom lived to almost 99. i want to beat her. >> reporter: that also means knowing your risk factors, including entering menopause, inactivity, smoking and drinking alcohol in excess. >> we have a crisis of fitness in this country. what we really need to do is get the 95% of women who are not exercising appropriately, exercising more. >> reporter: and that exercise is something carmella shares every day with her husband, knowing that she's the one that holds the key to her strength and well being. >> if you don't use them, you're going to lose them as you age. and i want to be able to enjoy my life and be able to do what i want to do as long as i can. >> reporter: it's important, because those strong bones will ward off osteoporosis and that fractured hip. it's free, gravity is your friend. so pick up those weights, start walking. it's one those things, brian, everybody can do it regardless of age. >> and, nancy, while we have

you, i know it's their marketing slogan, but aspirin was in the news again today. >> this time for cancer, along with other nonsteroidal anti-inflammatory drugs, naprosyn, ibuprofen. in a danish study published in cancer, over 18,000 people who took these drugs for several years had decreased cancer rates of malignant melanoma. and the other skin cancer, squamous cell cancer, dropped to 13% to 15%. not acetaminophen but the other class of drugs. another reason to talk to your doctor about perhaps using it as a supplement. not everyone can take it. pregnant women or children, anyone with a clotting disorder, it's not intended for you. >> dr. nancy snyderman, thank you, as always. up here next tonight, a perfect alignment that happens to be happening tonight.

had he lived he would have turned 95 today. he would be an aged and beloved former president. instead, at the grave of former president john f. kennedy, at arlington national cemetery, the site of the eternal flame, a wreath was laid today to mark his 95th birthday. nasa is taking steps now to preserve the steps they took decades ago on the surface of the moon. they are protecting american landing sites on the moon for historic preservation. presumably because you never know who or what will go back there. and there are a number of missions vying to go back with unmanned craft. they just wanted to declare the area off limits. because there's no air, wind with or weather, neil armstrong's footprints will never fade. they want to make sure they and all the others will remain undisturbed. tennis great serena williams has never lost in the first round of a grand slam tournament. going into today her record was

46-0. but that was until today. in a stunning three-hour struggle, france's own virginie razzano, ranked 111th in the world, pulled off a stunning upset. ousting williams 4-6, 7-6, 6-3. williams was the heavy favorite to win the tournament. she said she just made too many errors to win today. tonight here in manhattan, where the streets are laid out in a 200-year-old east/west, north/south grid, it's the twice yearly event known as manhattan henge. when the setting sun perfectly lines up with the cross streets to create some spectacular views. these are pictures from last year. our camera crews are busy recording pictures of tonight's beauty. we'll have that for you here tomorrow night. up next here this evening, a huge honor for a group of truly unique americans.

the medal of freedom is the highest civilian honor the u.s. can bestow. and today at the white house, president obama paid tribute to a new group of recipients, including bob dylan, toni morrison and legendary basketball coach pat summitt. here now a sampling from the day, once a year when america chooses to honor its very best.

>> this is a packed house, which is a testament to how cool this group is. first american to orbit the earth. john glenn became a hero in every sense of the word. >> god speed, john glenn. >> but he didn't stop there serving his country. as a senator, he found new ways to make a difference. and on his second trip into space at age 77, he defied the odds once again. toni morrison's pros brings us in a kind of moral and emotional intensity that few writers ever attempt. she believes that language arcs toward the place where meaning might lie. the rest of us are lucky to be following along for the ride. as the first woman to serve as america's top diplomat, madeleine's courage helped bring peace to the balkans and paved the way for progress in some of

the most unstable corners of the world. justice stevens applied throughout his career, his clear and graceful manner to the defense of individual rights and the rule of law, always favoring a pragmatic solution over an ideological one. when a doctor first told pat summitt she suffered from dementia, she almost punched him. as pat says, i can fix a tractor, mow hay, plow a field, chop tobacco, and call the cows. but what i'm really known for is winning. i remember in college listening to bob dylan and my world opening up because he captured something about this country that was so vital. ♪ well the times they are achanging ♪ >> there is not a bigger giant in the history of american music. >> it's worth watching all of it. we posted the full medal of

freedom ceremony with all the honorees on our website at nbcnightlynews.com. for us for now, that's our broadcast on a tuesday night. thank you for being here with us. i'm brian williams. we sure hope to see you back here tomorrow evening. good night. -- captions by vitac -- www.vitac.com good evening and thanks for joining us. i'm raj mathai. >> and i'm jessica aguirre. cops say they are the baddest of the bad and tonight nearly 100 criminals are off oakland's streets along with dozens of weapons. oakland police teaming up with federal agents to make some of the bay area's most dangerous streets a little safer tonight. nbc bay area's jodi hernandez joins us live with a look at that massive crackdown and, jodi, what comes next? >> reporter: that's a good question. we are told that this operation