good evening. we begin with that explosion that has 100 million americans wondering about the train tracks in their neighborhoods. outside columbus, ohio, in the dead of night, a train carrying ethanol derailed, a massive burst of flame 30 feet high. one eyewitness said it was as if the sun had exploded. hundreds of residents had to flee their homes. it is not often a blast this big is caught on tape and tonight, investigators are studying this film for clues as to what happened. abc's alex perez takes us to the site. >> jesus bloo[ bleep ]. >> reporter: a frightening boom -- an orange glow of raging flames visible as far as ten miles away. it was 2:00 a.m., and shawn wall had just come home after working the late shift. he grabbed his phone and started recording. what did it feel like on your skin? >> it felt like standing next to a bonfire, like, when i say that, i mean putting your hands like right there next to the heat and your skin is tingling and feeling as much pain as it could. >> reporter: it all happened after 11 cars of a massive freight train derailed outside columbus. three tankers, carrying some 90,000 gallons of ethanol exploded. authorities rushed door to door evacuating about 100 nearby homes. >> i thought it was maybe an electrical line. it was just a big ball of fire. >> reporter: luckily, there were no major injuries. the ntsb now has a team of investigators on the ground. >> we are gathering details at this time. >> reporter: across the country there are more than 140,000 miles of freight track criss-crossing our communities carrying dangerous cargo like ethanol, chlorine, sulfuric acid and nitrogen fertilizer. almost 100 million americans live close to a freight line and many local governments often don't know what's traveling through their backyards. >> they are not being notified in a routine way about this they basically have to work very hard to find out even what's coming through. >> reporter: and not knowing can be deadly. graniteville, south carolina, january 2005. a train carrying chlorine gas explodes and the fire department didn't have hazmat suits. they had to call for outside help. by the time it arrived, nine people were dead, 500 people injured. still, the head of the association of american railroads tells abc news the fear is largely unfounded and that 99.998% of all hazmat shipments reach their destination safely. the wreckage still smoldering here in columbus. authorities hope to have the fire fully extinguished by late this evening. those people who were evacuated should be back home sometime tonight. diane? >> all right, alex, thank you. and that video was extraordinary, the fiery explosion, shot by shawn wall, as you saw. it turns out, not long after he shot it, he helped pull one of his neighbors to safety. quite a night for that young man. and, now, we turn to an abc news investigation creating headlines today. the subject, the use of antibiotics in the chicken we eat. a new question has been raised about a possible relationship to an infection in women that is nearly impossible to treat. we should say the evidence is being hotly debated. dr. richard besser, our medical editor, will join us, but first, here's abc's senior national correspondent jim avila with his reporting here tonight. >> reporter: it's america's favorite food. 8.5 billion chickens raised for meat. nearly all of them, even the healthy, fed antibiotics from hatch to frying pan. a diet that a growing number of leading medical researchers around the world say has created a dangerous strain of e. coli, that is now highly resistant to anti biotic treatment. and here is what is new and alarming. they say that superbug in the bird is now infecting women. >> we're finding the same or related e. coli in human infections and in retail meat sources, specifically chicken. >> reporter: these top researchers say they now have strong evidence of a link between the disease and the chicken superbug. the grocery store meat carrying the same e. coli strain as the resistant strain causing painful and long-lasting bladder infections. same dna fingerprint. food and environment reporting network writer maryn mckenna interviewed the researchers, part of a joint investigation with abc news. >> when they looked at the infections and they looked at bacteria in the animals and bacteria on the meat, they all matched. >> reporter: and this is no ordinary infection. >> i couldn't function fully for weeks, almost a month. >> reporter: the superbug hangs on longer, resisting antibiotics, and comes back repeatedly as it did with atlan atlanta's dorie griggs. >> they ran the tests and confirmed that, yes, i still had the infection and let's try something else. >> reporter: veteran doctors say they often have to use several types of anti biotics now, trying to outsmart the bacteria. >> nay are very smart. we call them bugs, we think of them as stupid but they are very smart. >> reporter: the chicken industry disputes the research and says they believe that it's unlikely this supperbug comes from pul try at all. but the independent researchers say they are confident that the link is proven by the dna. diane? >> all right, thank you so much, jim. i want to bring in abc's dr. richard besser, who was acting held of the cdc and specialized in superbugs. we heard what jim said about some researchers, some scientists what they think. what do you think? >> reporter: i think the scientists are right. but i think it's going to be impossible to prove. and here's why. it's different from when you get a stomach bug, a stomach flu. there, you eat something and within a couple of days you are sick and you can actually test the food and see if it matches. >> trace it. >> reporter: exactly. here, if you eat contaminated chicken, that superbug can set up shop in your gut and may not be until months later that you get a bladder infection. there's no way to connect it. >> if you think the scientists are onto something, what do you do to prevent it. >> reporter: of course you want to keep your kitchen clean, but the solution is going to be on the farm. and cdc has been concerned about getting anti-bobiotics off the farm. you don't want to feed that to people. to animals that we're going to eat. and if you are a woman who has a bladder infection and you are not getting better, you have to go back and get tested. maybe you have a superbug that requires a stronger antibiotic, longer treatment. this is a big problem. >> if it keys recurring, consider this possibility? >> reporter: this could be the cause. >> all right, thank you dr. richard besser and also jim avila once again. now, we turn to the race for the white house, 118 days until your voice, your vote. and today, one of the conditions entered the political equivalent of a lion's den. mitt romney speaking to the naacp. abc's jon karl tells us what happened next. >> reporter: he knew it would be a hostile audience, but mitt romney came to the naacp convention anyway. and then, proceeded to tell them exactly what they didn't want to hear. >> i am going to eliminate every nonessential expensive program i can find. that includes obama care. and i am going to work to reform and save -- [ booing ] >> reporter: those boos lasted a full 15 seconds. romney then went on to slam president obama's record and added this -- >> if you want a president who will make things better in the african-american community, you are looking at him. take a look. [ booing ] >> reporter: talk about a tough sell. telling the nation's most prominent african-american organization to vote against the nation's first african-american president. afterall, in our latest poll, 96% of african-americans said they would vote for obama. just 3% for romney. >> thank you. >> reporter: romney won't find many votes here, he may find respect. showing he can stick to his beliefs before a hostile audience. romney did get a smattering of applause, including when he promised to return if elected president. for his part, president obama is not speaking at the convention this year. vice president biden is. during the campaign four years ago, john mccain came before this group, but he praised his then-opponent. >> he's inspished a great many americans. some of whom have wrongly believed that a political campaign could hold no purpose or meaning for them. the success should make americans, all americans, proud. >> reporter: after today's speech, a spokesperson for the naacp criteria sized what romney said, but gave him credit for showing up, saying, quote, we appreciate that he was courageous and took the opportunity to speak with us directly. diane? >> all right, jon karl reporting in from washington. and one more note have washington today. for the 33rd time, the house of representatives voted to repeal the president's health care law. it was mainly on partisan lines. of course, it's the law upheld by the supreme court, two weeks ago. as ever, the vote now goes to the senate, where it will almost certainly, once again, be voted down if it is even voted on at all. and overseas, another new sign of a serious crack in the brutal government of syria. a high profile defection. syria's ambassador to iraq declared in a statement, quote, i have joined the ranks of the revolution. he is the highest ranking diplomat to defect, joining 100 million tear officers and 15 generals who have switched sides. the ambassador joined fellow mobs of the ruling party to join him, saying president assad has used the party as, quote, an instrument to kill people and their aspirations for freedom. for the first time, we are hearing from the captain of a carnival cruise ship that sank in january, killing 32 on board. at the time, the captain was denounced by some passengers, for leaving the ship. abc's jeffrey kofman tells us what he's saying now. >> reporter: those piercing screams -- >> i'm getting pushed! >> reporter: the sound of 4,200 people scrambling for their lives when the "costa concordia" ran aground. 32 people would die. six months later, the infamous captain is finally speaking. >> translator: there is no scale for measuring the pain. >> reporter: francesco schettino offers condolences, but then says he has become a victim in this calamity, clearly resenting the captain coward label that he hounded him. >> i was forced to into into the lifeboat. i don't know if i slipped or fell. >> reporter: he takes every opportunity to duck responsibility. including for hitting the reef. >> translator: i did not have command, navigation was in the hands of an officer. >> reporter: but damning evidence shows he was in command. an italian newspaper published the contents of the black box data reporter. it shows he took the help six minutes before the collision. he does now admit he was on the phone at that critical moment. >> translator: i blame myself for being distracted. >> reporter: what about the one-hour delay in calling for help and ordering passengers to abandon ship? he insists he should be seen as a hero, that he saved lives because he waited until the ship drifted to shallower waters. this woman broke her collarbone when her lifeboat tipped during the chaos of the escape. >> he was a coward. at no point -- just fess up. he made a mistake but he's putting blame on everybody but himself. take the responsibility. it was his fault. >> reporter: he is facing charges of manslaughter and causing a ship wreck. jeff little kofman, abc news, london. and coming up on "world news," extreme turbulence. 15 seconds of terror at 30,000 feet. passengers afraid for their lives. and our reporter takes a wild ride of his own, to find out just how dangerous that really was. this is $100,000. we asked total strangers to watch it for us. thank you so much, i appreciate it, i'll be right back. they didn't take a dime. how much in fees does your bank take to watch your money ? if your bank takes more money than a stranger, you need an ally. ally bank. no nonsense. just people sense. for many, nexium helps relieve heartburn symptoms caused by acid reflux disease. osteoporosis-related bone fractures and low magnesium levels have been seen with nexium. possible side effects include headache, diarrhea, and abdominal pain. other serious stomach conditions may still exist. talk to your doctor about nexium. this is my grandson. and if it wasn't for a screening i got, i might have missed being here to meet him. the health care law lets those of us on medicare now get most preventive care for free like annual wellness visits, immunizations, and some cancer screenings. and that's when they caught something serious on mine. but we could treat it before it was too late. i'll be around to meet number two! get the screenings you need. learn more at healthcare.gov. you don't want to miss any of this! learn more at healthcare.gov. those little things for you, life's about her. but your erectile dysfunction - that could be a question of blood flow. cialis tadalafil for daily use helps you be ready anytime the moment's right. you can be more confident in your ability to be ready. and the same cialis is the only daily ed tablet approved to treat ed and symptoms of bph, like needing to go frequently or urgently. tell your doctor about all your medical conditions and medications, and ask if your heart is healthy enough for sexual activity. do not take cialis if you take nitrates for chest pain, as this may cause an unsafe drop in blood pressure. do not drink alcohol in excess with cialis. side effects may include headache, upset stomach, delayed backache or muscle ache. to avoid long-term injury, seek immediate medical help for an erection lasting more than four hours. if you have any sudden decrease or loss in hearing or vision, or if you have any allergic reactions such as rash, hives, swelling of the lips, tongue or throat, or difficulty breathing or swallowing, stop taking cialis and get medical help right away. ask your doctor about cialis for daily use and a 30-tablet free trial. it was a harrowing ordeal aboard an american airlines flight from aruba to miami. severe turbulence shook the plane for 15 seconds, jolting the 200 passengers and crew. about a dozen people needed medical care when they landed. many said they were terrified, but just how much danger was there, really? abc's matt gutman took his own bumpy ride today to find out. >> reporter: violent jolts, sending passengers into hushed prayer on a jetblue flight last year. intense shaking on a 2009 continental flight, kills one person and injured several others. and tuesday, for 15 harrowing seconds, turbulence panicked passengers on flight 1780 from aruba to miami. >> we were going to die. we were going to die. it was scary. >> reporter: the american airlines boeing 757 was 30,000 feet up when unbuckled passengers were suddenly tossed, like coins in a can. 12 people were injured. five were hospitalized. in a statement to abc news, american airlines says, "the seatbelt sign was on at the time, and nothing on the radar indicated that turbulence was in the area." a plane flying in clear skies can be rocked by a column of air from a storm thousands of feet below. severe turbulence can cause that plane to plunge up to 50 feet. turbulence is the leading cause of injury to airline passengers and flight attendants. on average, injuringing 58 people a year. to feel that type of turbulence, we took off with flight instructor charlie rodriguez in a simulator. >> it could go from moderate to severe in like a second. >> reporter: this is what they call moderate chop. now, the plane could be flopping up and down 15 to 20 feet. and light chop, it's more like a couple of inches. but in the back of the plane, they're feeling this is a lot more than we are here in the cockpit. and pilots mean it when they flick on that seatbelt sign. >> if you get into severe turbulence, and you're not with your seatbelts on, you're going to get hurt. >> reporter: but chances are, you won't get killed. over the past 30 years, only three people have died from turbulence. it turns out you're more likely to get hit by a meteor. matt gutman, abc news, miami. and coming up, healthy living. a new study with a new reason why a glass of wine with dinner can keep you healthy. ♪ [ slap! ] [ slap! slap! slap! ] [ male announcer ] your favorite foods fighting you? fight back fast with tums. calcium rich tums goes to work in seconds. nothing works faster. ♪ tum tum tum tum tums sleep in my contacts. nothing works faster. relax... air optix® night & day aqua contact lenses are approved for up to 30 days and nights of continuous wear, so it's okay to sleep in them. visit airoptix.com for a free 1-month trial. [ male announcer ] we believe small things can make a big difference. like how a little oil from here can be such a big thing in an old friend's life. purina one discovered that by blending enhanced botanical oils into our food, we can help brighten an old dog's mind so he's up to his old tricks. with this kind of thinking going into our food, imagine all the goodness that can come out of it. just one way we're making the world a better place... one pet at a time. vibrant maturity. from purina one smartblend. one pet at a time. last season was the gulf's best tourism season in years. in florida we had more suntans... in alabama we had more beautiful blooms... in mississippi we had more good times... in louisiana we had more fun on the water. last season we broke all kinds of records on the gulf. this year we are out to do even better... and now is a great time to start. our beatches are even more relaxing... the fishing's great. so pick your favorite spot on the gulf... and come on down. brought to you by bp and all of us who call the gulf home. mine was earned off vietnam in 1968. over the south pacific in 1943. i got mine in iraq, 2003. usaa auto insurance is often handed down from generation to generation. because it offers a superior level of protection, and because usaa's commitment to serve the military, veterans and their families is without equal. begin your legacy, get an auto insurance quote. usaa. we know what it means to serve. and now, healthy living. a brand new study out of oregon state university finds that alcohol, most like wine, could be a weapon against bone loss in women. a group of moderate drinkers stopped drinking and within two weeks, their bones were losing strength. but when they started again, their bones looked healthier almost immediately, within 12 hours. and, by the way, moderate drinking is defined as two five ounce glasses of wine a day. and, a remarkable story of love lost and found. a man in texas, bob bruszle, never lost home that one day he'd find his beloved sports car, an austin healy. it was stolen from him outside his home in philadelphia 42 years ago. well, today, we are happy to say, man and car are together again. he spent years faithfully scouring online sites and finally found it on ebay, listed under a dealer in beverly hills. he contacted police, he got it back and by the way, says, it still runs. and, the countdown is on, now two weeks until the olympics. and today, we learned that for the first time in history, the women outnumber the men on team usa. 269 to 261. the team including 13 moms, at least four sets of sisters, that's venus and serena williams among them. and by the way, the oldest and youngest female athletes at the olympic games are both americans, a 54-year-old equestrian, a 15-year-old swimmer. and, speaking of the olympic team, they're the best america has to offer. so, why are their uniforms made in china? our made in america team is on that case.n my right side. an intense burning sensation like somebody had set it on fire. and the doctor said, cindie, you have shingles. he said, you had chickenpox when you were a little girl... i said, yes, i did. i don't think anybody ever thinks they're going to get shingles. but it happened to me. for more of the inside story, visit shinglesinfo.com ...more talk on social security... ...but washington isn't talking to the american people. [ female announcer ] when it comes to the future of medicare and social security, you've earned the right to know. ♪ ...so what does it mean for you and your family? [ female announcer ] you've earned the facts. ♪ washington may not like straight talk, but i do. [ female announcer ] and you've earned a say. get the facts and make your voice heard on medicare and social security at earnedasay.org. c'mon, michael! get in the game! [ male announcer ] don't have the hops for hoops with your buddies? lost your appetite for romance? and your mood is on its way down. you might not just be getting older. you might have a treatable condition called low testosterone or low t. millions of men, forty-five or older, may have low t. so talk to your doctor about low t. hey, michael! [ male announcer ] and step out of the shadows. hi! how are you? [ male announcer ] learn more at isitlowt.com. [ laughs ] hey! his morning starts with arthritis pain. and two pills. afternoon's overhaul starts with more pain. more pills. triple checking hydraulics. the evening brings more pain. so, back to more pills. almost done, when... hang on. stan's doctor recommended aleve. it can keep pain away all day with fewer pills than tylenol. this is rudy. who switched to aleve. and two pills for a day free of pain. ♪ [ female announcer ] and try aleve for relief from tough headaches. and finally, the official uniform of the u.s. olympic team has been unveiled. and while all of us love team usa, not everybody applauded the new look. so, what caught our eye here at "world news" was the label. the u.s. uniforms were made in china? how could it be? sharyn alfonsi and our made in america team set out to get answers. >> reporter: they are the pride of america, team usa. and for the opening ceremonies in london, they'll proudly be wearing red, white and blue, classic american style by ralph lauren. but just how american is it? we sent our producer and intern to get outfitted in the opening ceremony uniform. you look dashing! >> thank you very much. >> reporter: and then we dug in, looking at the labels. made in china. china. china. and the shoes? made in china. every item in those uniforms, made overseas. what do you think about that? >> it's a national disgrace. all of the olympians need to be american, our uniforms should be made in america. >> reporter: so, your reaction when i tell you that that outfit top to bottom, none of it is made in america. >> i'm shocked. >> reporter: lanette is one of the country's top fashion designers. could we have outfitted them in american products? >> absolutely. >> reporter: she says american manufacturers could have made the uniforms here and for less money. >> why shouldn't we have pride, not only in the american athletes, but in the american manufacturers and laborers who are the backbone of our country? what's wrong? why was that not a consideration? >> reporter: so, we reached out to ralph lauren and the olympic committee to ask. the committee respond eed -- th team is privately funded and we're grateful for the support of our sponsors. we're proud of our partnership are ralph lauren, an iconic american company. not exactly an answer. but american manufacturers insist, like our athletes, they can compete. sharyn alfonsi, abc news, new york. >> and, by the way, of all the olympic clothing was made in america, it could keep a billion dollars from heading overseas this year. thank you so much for watching. check in at abcnews.com. "nightline" later. and we'll see you tomorrow. good night. [ male announcer ] now at your neighborhood subway: the new santa fe steak melts. get extra grande flavor with the santa fe steak & bacon melt. juicy steak, crispy bacon, and melted cheese with creamy santa fe caesar. or try adding egg for a santa fe steak, bacon & egg melt -- a favorito for breakfast but muy bueno any time of day. get to your local subway and claim your steak today -- with new santa fe steak melts. subway. eat fresh. captioned by closed captioning services, inc.