Game, but they sell out immediately. Tonight, the surprise reason why youre getting shut out. And makeover barbie. The biggest change in the history of an american icon. Nightly news begins right now. Announcer from nbc World Headquarters in new york, this is nbc nightly news with lester holt. Good evening. To a lot of people, the republican race for president may be feeling more and more like a reality show tonight starring a man who before he became a candidate proved he could draw an audience. And so donald trump will likely have a lot tonight. Either the Republican Debate hes now vowed to boycott or his own event that could steal leading up to all this, a public duel with fox news, public reconsider, even primetime discussions of milkshakes. All just four days until the vote in iowa. Nbcs Peter Alexander explains. Republicans final showdown before the iowa caucuses, instead Donald Trumps noshow is stealing the spotlight. The frontrunner staging his own primetime event to raise money for veterans. Going headtohead on tv with the fox news debate just three miles away. Even drawing a pair of his underdog opponents, Mike Huckabee and rick santorum. In a lot of ways youre not giving them im not walking away. I was pushed away. Im not walking away. Reporter trump is defiantly positioning himself as the deal maker in chief. Its called an eye for an eye. I bought you so many vanilla milkshakes, you owe me. You can do that any day. Reporter today the billionaire launched this fundraising website claiming 100 of donations will help vets. The campaign wont say exactly where the money will go. Canines for warriors tells nbc news the them late today saying theyre one of 18 nonprofits now under consideration. But a separate Veterans Group is skeptical tweeting, money doesnt need to be funneled through a political campaign. Will trumps debate boycott backfire . His opponents say yes. Afraid of me. Hes afraid of you. Reporter still, trump has momentum and now the lead here in iowa. According to the latest nbc news poll. What are the risks for donald trump . The risks for trump is he looks weak by not confronting his opponents. The upside is, he avoids being the pinata at the Republican Debate. Reporter marco rubio rising in the polls, already taking a swing. Show. Greatest show on this is not a show. This is serious. Reporter late tonight another twist, Donald Trumps campaign confirms to nbc news that trump would be willing to debate ted cruz one on the canadianborn senator gets a federal judge to rule on his eligibility to be lester . All right, Peter Alexander, thank you. On the democratic side of the race, our brandnew poll Shows Hillary clinton and Bernie Sanders locked iowa. Debating over whether to hold more debates. Meantime, clinton is also getting drawn away from the trail to raise more money. Something her opponent on. We get details from nbcs andrea mitchell. Reporter its a dead heat for the democrats in iowa. Our new poll shows a close poll. The vermont senator has a commanding 19point lead in new hampshire. Competitive, both are now agreeing to more debates, including hampshire, if the Democratic Party approves. The political world bit. Clinton would like another debate. You know what, i said, thats fine, i dont mind that. Reporter facing a longer than expected primary contest, clinton left iowa wednesday afternoon to go to philadelphia to raise money from an investment firm. Some of my supporters, including my good friend jon bon jovi had a fundraiser for me. Reporter but clintons fundraisers plays right into sanders critics. How does wall it . Millions in campaign distributions and speaking fees. Why isnt that a negative ad . Does it mention nope. Does it have any clinton . Nope. Arent you suggesting im not suggesting anything at all. Reporter tonight clinton returned to iowa, and sanders who at 74 would be the elected president if he wins. Good health. Not with me. It was a tough decision. Do i get involved in senior boxing, challenge go for the light heavyweight championship, or run for president. I decided to run for president. Reporter Hillary Clinton is back in iowa tonight. She only just took the stage tonight, though. Because this contest is so tough, she repeatedly has to go back to fund raise from the big donors, unlike sanders who has more than 2. 5 million online contributors. Andrea mitchell, thanks. Our political director, the moderator of meet the press, chuck todd. Youre in iowa. Four days until the caucuses. How is this playing there . Any signs of a blowback on the ground there . Not from anybody thats thinking about supporting trump. And thats probably good news for him. Look, he has figured out a way to steal the spotlight from this debate before it started. And theres already a lot of rumors circulating around here that he may steal the spotlight after the debate is over, that maybe he shows up in the spin room, or he figures and thats been his campaign in a nutshell is he figures out how to almost pull the rug out from under his opponents. As for the debate tonight, i think its actually fascinating that trumps not onstage, and instead the focus will be on ted cruz and marco rubio. The other big news in our new nbc news wall street poll has rubio up, now in a strong third place position. What does that mean . Ted cruz is hammering rubio with a new attack ad. Tonight, lester, rubio v. Cruz, this actually could be the showdown worth watching, and the one that could extend if trump falters. A lot of things in play. Chuck, thanks. A program note, last night we talked to Bernie Sanders, tomorrow night well have my conversation with Hillary Clinton on the trail in iowa. The final sprint before the voting begins. A warning now from the World Health Organization that the zika virus is, quote, this year alone, 3 million to 4 million in north and south america could be infected with the virus linked to birth defects. The cdc said the number of people returning to the u. S. With zika is growing. Nbcs tom costello has more. Reporter dr. Whitney prince is one of a few americans who has experienced the zika virus as a patient. It was on her honeymoon in bora bora that she contracted zika through a mosquito bite. Once home she developed a skin rash, conjunctivitis, and a headache. Worn out, tired, kind of dragging. I actually ended up staying out of work for about a day and a half mainly because of the joint pain because it was painful to walk at that point. Reporter dr. Prince recovered and she was not pregnant. In brazil today, nbc news was with a 20yearold as she visited her doctor. Her 2monthold is one of thousands of babies who have been born with microcephaly in while zikacarrying mosquitoes have not turned up in the united states, cases have turned up in 11 states and d. C. They contracted zika while abroad. 19 in puerto rico and 1 in the virgin islands. Experts some zika mosquitoes will arrive states, they dont expect a massive outbreak. There is always the slight possibility that we might see a major outbreak. We dont think thats going to occur. But were going to be prepared for it. Reporter the reasons for the optimism, theres far less trash and stag nast water in u. S. Urban areas. Cities and towns spray for mosquitoes here. Cold weather acts as a barrier. And americans use air conditioning and window screens to keep mosquitoes out. Meanwhile, gina park is 18 weeks pregnant. She and her husband have now canceled an Upcoming Trip to mexico. We just thought it wasnt worth the risk. We just probably ever did happen. Reporter meanwhile, the National Institutes of health today said it hopes to start clinical drug trials this year, but a zika vaccine could be years away. Tom costello, nbc news, washington. A mystery that played out hours late this afternoon in the new york area, as reports started to stream in of what felt like an earthquake from the jersey shore all the way to long island and connecticut, prompting a flurry of 911 calls. Turns out it was actually a series of sonic booms caused by a military f35 fighter jet based in maryland. Conducting flight tests up the new jersey coast. Mystery solved. Just a lot of frayed nerves left behind. And we have breaking news on the tense stalemate in oregon, the federal refuge seized by antigovernment protesters. Four holdouts remain and were hearing a convoy has left the checkpoint, and the roadblock has been removed. Signs that things may be coming to a conclusion there. The leader had urged bundy was arrested tuesday when violence erupted during a traffic stop and left one member of his group dead. Weve got an extraordinary access into iran. And in a rare interview, the american educated head of Irans Nuclear program reveals to Nbcs Richard Engel neverbeforeheard details about the controversial deal that lifted International Sanctions on iran. Reporter little is known about how iran ended up making a deal with its old enemy, the united states. But now in the First American interview since the deal, the head of Irans Atomic Energy Organization told nbc news his countrys Supreme Leader is eye dole la entrusted him with hammering out the details of the nuclear agreement. Within limits. He said, i do not trust the americans, but okay, i trust you. You give it a try and see what you can do. Reporter ali, an scientist, reveals for the first time the condition the Supreme Leader set. One condition was that, look, you just discuss the nuclear issue, you know, no political negotiations. Reporter the ayatollah also insisted talks had to be quick and preserve irans right to enrich uranium. The fourth condition was the condition that lets you dont want to say what it is even now . Not now. Reporter but he did want to talk about taking relations with the u. S. To a level not seen since american diplomats were taken hostage at the u. S. Embassy here 36 years ago. Relationship, industrial cooperation, cultural cooperation american factories opening here, is that what we welcome them, yes, if they want. Why not. Reporter but trust is hard to build. This photograph, our nuclear martyrs. Reporter he keeps office of four Nuclear Scientists and a driver assassinated in an effort to slow Irans Nuclear program. He claims israel did the killings, with washingtons tacit approval. Allegations washington denies, and israel wont confirm. Theres a space here. Do you think there will be a sixth . Obviously you dont want that i hope its me. I hope its me. You hope its you . Yeah. Because this is a source of pride. I told you. Yeah. We look for martyrdom. Reporter a wide gap still exists between the u. S. And iran, and the zeal of its revolution remains just below the surface. Richard engel, nbc news, tehran. There is more to tell you about here tonight. Did you get shut out for adele tickets . Or maybe you paid double to see the boss . Investigators say youre playing a fixed game. How they plan to track down on it. Also, barbies getting a new look, several of them in fact, after years of criticism. Carry the centimeter, [ beeping, whirring ] great caesar salad and now the name your price tool shows people policy options to help fit their budget. Is that a true story . Yeah people really do save an average of over 500 when they switch. I mean about you inventing it. I invented the story, and isnt that what really matters . So. What else about me . I am totally blind. And sometimes i struggle to sleep at night, and stay awake during the day. This is called non24. Learn more by calling 8448242424. Or visit your24info. Com. Listen up im here to get the lady of the house back on her feet. And give her the strength and energy to stay healthy. Whos with me . the complete balanced nutrition of great tasting ensure. With 9 grams of protein. And 26 vitamins and minerals get fastacting, longlasting relief from heartburn with it neutralizes stomach acid and is the only product that forms a protective barrier that helps keep stomach acid in the stomach where it belongs. For fastacting, longlastingvrelief. Try gaviscon. Its just a cough. If you could see your cough, youd see just how far it can spread. Robitussin dm max soothes your throat and delivers fast, powerful cough relief. Robitussin dm max. Because its were back now with a major new investigation blowing the lid off the reason so many people get shut out when trying to buy tickets for a hot concert or sporting event. Chances are its happened to you, and its not because so many people are clambering to go. Investigators say its a fixed game. As nbcs jacob ras cope reports now, theyre fighting back. Everything about adele is spectacular, fans will tell you, except be to score a ticket its a worldwide problem for so many of the hottest events. Why is it often so difficult to get tickets at face value . Were releasing today a report reporter now, a threeyear investigation by the new York State Attorney general reveals tickets are never available to begin with. Artists, promoters, venue operators will hold back a large number of tickets that never make it to the regular market. Reporter according to the report, some shows had 70 of tickets earmarked for presale events. The report also found that one Ticket Broker using a hightech purchasing technique called a bot can immediately scoop up tickets for resale. In one example someone bought more than 1,000 tickets in one minute for u2s performance at Madison Square garden last year. Its a dilemma that has artists from elton john to cold play crying foul, and many fans steaming. So frustrating. Heartbreaking. You know theyre doing it purposely just so times the price. Problem. Its everywhere. I cant think of a state in the country this isnt a problem. And it happens at every major concert venue. Reporter your best shot at landing those musthave tickets, experts say register for fan clubs to get early access. But even then theres no guarantee leaving so many fans on a sour note. Jacob rascon, nbc news, new york. When we come back, years ago today . The question so many are asking tonight as we remember an american tragedy. They say when mr. Clean saw all the Different Things his new smart phone does. It reminded him of his magic eraser. Its not just for marks on walls. Its tough on kitchen grease. And bathroom grime too. Hes your. All aroundtoughcleaner, mr. Clean. Today people are coming out to the Nations Capital to support an important cause that can change the way you live for years to come. How can you help . By giving a little more, to yourself. I am running for my future. People sometimes forget to help themselves. The cause is retirement, and today thousands of people came to race for retirement one percent of their income. If we all do that we can all win. Prudential bring your challenges seems like weve hit a road block. That reminds me. Anyone have occasional constipation, diarrhea. Gas, bloating . Yes probiotic cap each day digestive issues. Bacteria. Live the regular life. Phillips. music woman i ll never remember all the projects, presentations, or meetings i gave up my nights for. music s drums intensify but days like this, i ll never forget. Get out there, be unstoppable. This is my fight song take back my life song music it was exactly 30 years ago when seven crew members boarded the Space Shuttle challenger and set off on an adventure. But 73 seconds later, the moment is seared into the memories of it live and many more who saw it replayed. The mission ended in a tragic disaster in the sky. Takes us back to the moment that forever changed space exploration. Reporter on a clear but unusually cold Cape Canaveral morning. Space shuttle challenger left this earth and headed for space, filled with anticipation and hope. But at 11 39 Eastern Standard Time we have just seen the launch of the Space Shuttle challenger. There has been a major problem. Reporter the shuttle tragically disintegrated high over the atlantic. Its crew of seven, gone. Including crista mccallive, the First Teacher in space. Her parents watched at the cape. Her students were hampshire. Others watching across the country would teachers themselves. Today at ceremonies from Arlington National cemetery, to Cape Canaveral, wreaths were laid in remembrance. We are still reaching for the stars, from the mars rover on the red planet, to stunning new pictures of pluto from the probe new horizons. And, of course, the International Space station where today a moment of silence was held. But it was on that january night three decades ago that president Ronald Reagan postponed his state of the Union Address to deliver his poignant remembrance. The future doesnt belong to the feint hearted, it belongs to the brave. The challenger crew was pulling us into the future, and well continue to follow. Reporter kevin tibbles, nbc news, chicago. There is a big change coming for new moms in the military. The pentagon announced that it will now grant 12 weeks of maternity all branches. The good news for the army and air force because it doubles their leave time, bad news for the navy and marines because it cuts their leave back from 18 weeks. When we come back here tonight, barbie is breaking with the past. Why the iconic doll line is getting a historic makeover. What if one piece of kale could protect you from diabetes . What if one situp could prevent Heart Disease . One. Wishful thinking, right . But there is one step you can take to help prevent another serious disease. Pneumococcal pneumonia. If you are 50 or older, prevnar 13 vaccine can help protect you from pneumococcal pneumonia, an illness that can cause difficulty breathing, and may even put you in the hospital. Even if you have already been vaccinated with another pneumonia vaccine, prevnar 13 may help provide additional protection. Prevnar 13 is used in adults 50 and older to help prevent infections from 13 strains of the bacteria that cause pneumococcal pneumonia. You should not receive prevnar 13 if you have had a severe allergic reaction if you have a weakened immune system, you may have a lower response to the vaccine. Common side effects were pain, redness or swelling at the injection site, limited arm movement, fatigue, headache, muscle or joint pain, less appetite, chills, or rash. Get this one done. Ask your doctor or pharmacist about prevnar 13 today. I am totally blind. And sometimes i struggle to sleep at night, and stay awake during the day. This is called non24. Learn more by calling 8448242424. Or visit your24info. Com. Hi, im here with some advice from the future dont buy makeup that settles into lines, it ages you. Get simply ageless makeup it floats over lines and you look beautiful simply ageless from olay. And easy, breezy. When heartburn hits fight back fast tums smoothies starts dissolving the instant it touches your tongue and neutralizes stomach acid at the source tum, tum, tum, tum smoothies only from tums ryou do all this research on the perfect car. Rgas mileage, horse power, torque ratios. Rthree spreadsheets later, r you finally bring home the one. Then smash it into a tree. P your Insurance Company is all too happy to raise your rates. Maybe you shouldve done a little more research on them. For drivers with accident forgiveness, Liberty Mutual wont raise your rates due to your first accident. In a whole new light. Finally tonight, a historic change for one of the most popular toys of alltime. For generations, barbie dolls have presented an image of perfect beauty. For many, thats exactly the problem. But now as nbcs erica hill tells us, barbie is getting a whole new look. Reporter since barbie debuted in 1959, shes tried just about every job. But one thing that never changed, her figure. Until today. When toy maker mattel introduced three new barbie body types to shapes and sizes of petite, tall, and curvy. I think its about shape. Reporter critics had long complained barbies body was an impossible ideal, and pressure for more physically realistic dolls. Mattel went back to the drawing board, and introduced more diverse options. Society felt that barbie needed to be more in touch with the times and a better reflection of the world were living in today. Reporter while barbie remained a bestseller for mattel, 92 of american girls 3 to 12 have owned one of the dolls. Sales plunged 20 from 2012 to 2014. A slide that continues into 2015. More and more brands are recognizing that women and girls as consumers and as audiences, they need more, they demand more, they want more, and theyll spend more. Reporter mattel is hoping the new dolls Available Online now, in stores this march, will help to boost sales. Times are changing. Life has changed. Were all different shapes, different colors, different ethnicities. Reporter it just may be barbies freshest look ever. New york. And that will do it for us on this thursday night. Im lester holt. For all of us at nbc news, thank you for watching, and good night. The Parker Police officer who saved a teenager from a frozen retention pond is talking about that day. 2 weeks ago 3 boys fell into the water. He pulled one out and did his best to save the other 2. Victoria sanchez talked with him today