Of tourists attend one of the worlds biggest celebrations. And the hidden war being fought in communities amid an epidemic thats risen to the number one concern for voters in the nations first primary. Nightly news begins right now. Announcer from nbc news World Headquarters in new york, this is nbc nightly news with lester holt. Good evening. Facing a primary showdown in New Hampshire just six days from now, donald trump is talking about a doover in iowa where he came in second place behind ted cruz. In a twitter tirade, hes accusing cruz of playing dirty tricks to pull off mondays win, but trumps not the only candidate sounding off about cruz who is busy barnstorming through New Hampshire with a wind at his back and apparently a target on his back. Nbcs Hallie Jackson tells us more. Reporter while republicans push ahead in New Hampshire, back to iowa, sparking a new feud with the man who beat him there. Ted cruz didnt win iowa, trump tweeted. He stole it. Adding either a new election should take place or cruz results nullified. Its one of trumps harshest attacks, less than 48 hours after one of his most gracious moments. I want to congratulate ted. Reporter trump echoing complaints from ben carsons campaign accusing cruz staffers of dirty tricks for insinuating on caucus night carson might drop out, trump calling it voter fraud on Boston Herald radio. One of the most disgusting things, said he was quitting the race and to vote for him. Reporter hes calling you a cheater, calling you a fraud. Does this cross the line for you . Listen, donalds insults get more and more hysterical the more and more upset he get. Reporter do you think they are fun . I think they are very funny. I wake up every day and laugh at the latest thing donald has tweeted because hes losing it. Reporter cruz isnt under any investigation, but late today carson said there were people who tried to take advantage of a situation, who tried to distort information. Reporter cruzs rivals piling on ultimately i think it goes back to what i said before and that is the willingness to say or do anything, in this case spread a false rumor about ben carson. Reporter marco rubio, trump and the rest of the field now focused on organization, trump beefing up his with seven phone banks, volunteers from four states here, the frontrunner so dominant in recent polls some establishment candidates may need a hand, and jeb bush is asking for it. Get back in the business of creating a more peaceful world. Please, clap. Reporter tonight bush and the rest of his republican rivals have a little less competition. Rick santorums expected to drop out tonight, and rand paul suspended his campaign today. Many of his libertarianleaning backers in New Hampshire here expected to shift their support to ted cruz. Lester . Hallie jackson, meantime, are trading some of their sharpest attacks yet in New Hampshire. Even though Hillary Clinton was declared the winner in iowa, albeit by a thin margin, the sanders camp says he got a huge fundraising boost after the caucuses, 3 million in just 24 hours. We get more from nbcs andrea mitchell. Reporter the democratic battle in New Hampshire is heating up with the candidates today going after each other as never before. So i hope we keep it on the issues because if its about our records, hey, im going to win by a landslide. I am for a positive, progressive, economic agenda. Reporter taking aim at this sanders hunt after clinton called herself a reporter do you think hill shill a progressive . Some days, yes. Except when she a proud moderate, and then i guess shes not a progressive. Good day for progressives when i helped to get 8 million kids Health Reporter barely avoiding an embarrassing defeat in iowa, clinton comes to New Hampshire behind by double digits. Can she repeat her 2008 comeback win over barack obama . I listened to you, and in the process ive found my own voice. Reporter this time her campaign is trying to lower expectations against the vermont senator. This is a steep climb in New Hampshire. This is Bernie Sanders backyard. Reporter that prompted sanders to say clinton was insulting New Hampshire voters. I think that that argument, that the only reason that were doing well hopefully here in New Hampshire is because were from a neighboring state is not totally true. Reporter also attacking her for making big money in the past from paid speeches from wall street banks and colleges. Earning 200,000 plus, ive got a real problem with that. Reporter the pressure is on sanders. If he doesnt do well here, the road gets tougher for him in nevada, south to super tuesday with more minorities, many backing clinton. And tonight bill clinton is campaigning in South Carolina for his wife as sanders has just become a tougher challenger. He got secret Service Protection for the first time today, and dozens of clinton aides have driven her from brooklyn now to be here with this campaign. She is now delaying a planned fundraising trip to boston. She will stay here in New Hampshire now through the primary. Lester . Andrea mitchell with the debate stage behind her and a reminder, chuck todd and Rachel Maddow will moderate the democratic debate on msnbc tomorrow night live from the university of New Hampshire in durham at 9 00 eastern time. Theres late word that the criminal Sexual Assault case against Comedian Bill Cosby will move forward. A judge has thrown out a defense motion to dismiss the case which dates back to 2004. Nbcs Stephanie Gosk is outside the courthouse in norristown, pennsylvania. Stephanie . Reporter good evening, lester. Well, the defense team for cosby was trying to get this case that the District Attorney in 2005 promised their client that he would never be charged criminally for the Sexual Assault of Andrea Constand thereby having him sit for a civil deposition. However, the judge here heard two full days of testimony from that District Attorney saying he actually didnt find enough evidence to prosecute the case, and he also said he wanted to create an environment to give Andrea Constand some form of justice, but ultimately the judge decided that there was not actually a binding promise not to prosecute, and this case will go forward. You can expect cosbys team to appeal that decision. Stephanie gosk, thank you. Now to the midair mystery over what blew a giant hole in a passenger plane over somalia. It could have been just a horrific accident, but there are growing fears it could also have been caused by a bomb on board. We get the latest on nbcs keir simmons. Reporter the moments after an explosion ripped a hole in the cabin of a commercial airliner, oxygen masks flapping as it descends from 12,000 feet. People on board claim a burning man was skukdofsucked out while most passengers stunningly calm walked safely away. I heard a big bang and smoke erupted, you know. We couldnt see anything for a few seconds. Reporter tonight experts are studying the images for clues. Its evident from the pictures that the explosion or the failure of that fuselage happened from inside out. That means it looks like it originated inside the cabin and blew the structure outward. Reporter could it reporter could it have been a bomb or a failure of the plane . A united 747 from its fuselage in 1989. Passengers torn from the seats, while in 2011 a southwest flight from phoenix to sacramento lost part of its roof. Metal fatigue was blamed. Then theres attempted terrorism, richard reid tried to detonate explosives in his shoes on a 2001 miami flight, and in 2009 Omar Abdulmutallab hid explosives in his underwear in a detroitbound plane. An official in somalia from this weeks flight told nbc news no shrapnel has been found and the cause is unclear but the country is home to Al Qaedalinked extreme extremists who claim they blew apart a plane last year in egypt. Had the occasion occurred closer to the fuel tanks this plane might have suffered the same catastrophic fate. Keir simmons, nbc back in this country across the south, millions of people are facing Severe Weather once again after a series widespread damage last night, and as nbcs jacob rascon reports areas was the small town of collinsville, coming right at us. Reporter there was no time to be afraid, many say. Only time to run. This door here is just blown out. Reporter pastor wade ricks and his wife julie jumped under a desk and prayed. What is the prayer . Lord, save us. Save us. Thats what she prayed, over, just, lord, save us, and and he did. Reporter the church where they were hiding, however, was not saved. All three buildings torn to shreds, but for the faithful at First Baptist there is a lesson in the rubble. Thats what this storm is about. Were going to learn to walk with god, and youre going to see whether we really believe what we say we believe. Reporter nearby a neighborhood in shambles. For some there is little worth saving. Vicky hartley and her husband had just moved in. This is it. This is the workshop where i was, yes. Reporter the only room untouched. Was just a roar and a lot of shaking. Reporter and Severe Weather is on the move. Flash flood watches or warnings for more than along the east coast with whiteout conditions and icy roads in south dakota, following days of heavy snow. In the south dozens of many damage or destroyed homes and flooding roads left impassable. 92yearold luna farrell had to be rescued from her home by boat. Will you rebuild it . Oh, yeah, well rebuild. Reporter in collinsville they survived a tornado that destroyed their church, losing almost everything, but not their faith. Local Authorities Say it is amazing that in all of the tornado damage in the south nobody was reported injured or killed, and tonight in this region already so battered by Severe Weather there are new reports of tornadoes and the threat continues overnight. Lester . Jacob rascon tonight, thanks. With zika cases on the rise in florida, today governor rick scott declared a Public Health emergency in four counties, and while theres concern about the virus impact on rio, brazilian officials have a more immediate challenge, protecting the millions of tourists arriving for carnival this week. Rehema ellis reports on that effort from the city thats the epicenter of this outbreak. Reporter its just after dawn in recife, and the battle is raging against the zikacarrying mosquito, aedes ajepti. Health Department Workers armed with tanks full of pesticide rushing to spray streets, alleys and parks. It works very quickly, and soon all the mosquitos are flying around will be dead. Reporter attacking the mosquito problem here is a big priority because this weekend these streets will be filled with more than a Million People for carnival. Without protection, all of them are vulnerable. These tourists knew the risks but came anyway. Im using bug spry to try and prevent getting bit. Reporter and hes going to need it. Like many mosquitos unsanitary conditions. Unlike other mosquitos, this species bites during the day instead of spiking at dawn and dusk. It also lives inside homes and can survive under beds, on walls and in closets. People provide it with everything it needs. In fact, you often mosquito unless theres a large enough sustain it. Reporter these mosquitos were widespread in the americas during the 1930s. Aggressive control efforts, including the insecticide ddt, drastically cut their population by the 70s, but now they are surging again. From Health Officials in los angeles. Eliminate mosquitobreeding conditions. That means taking buckets, flower pots, trash, recyclables and getting rid of them. Standing water is their eggs. Reporter Scientists Say the hotter it gets in brazil and elsewhere, the greater the risks these mosquitos can rehema ellis, nbc news, recife, brazil. Real estate heir robert durst is now one step closer to a murder trial. Durst pleaded guilty in new orleans today to illegally possessing a firearm. The gun was found when durst was arrested last march out of concern he would flee the country. Under a plea deal, durst will be sentenced to more than seven years in prison. It could also clear the way to return him to los angeles to face trial for the 2000 murder of friend susan berman. Still ahead tonight, the deadly epidemic tearing families apart in New Hampshire and the crucial role its playing on the campaign trail. Also, there is a 63 million Lottery Ticket out there somewhere, but time is running out to cash it. The microsoft cloud allows us to access information from anywhere. The microsoft cloud allows us to scale up. Microsoft cloud changes our world dramatically. It wasnt too long ago it would take two weeks to sequence and analyze a genome. Now, we can do a hundred per day. With the microsoft cloud to build server rooms. We have instant scale. The microsoft cloud is helping us to rebuild and reinterpret our business. This cloud helps transform business. This is the microsoft cloud. 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. 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. If you are 50 or older, one dose of the prevnar 13 vaccine can help protect you from pneumococcal pneumonia, an illness that can cause coughing, chest pain, 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 to the vaccine or its ingredients. 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 welcome back. With all eyes on New Hampshire, were turning the spotlight on a major problem hitting home in that state. New hampshire has one of the highest drug addiction rates per capita in the nation, and polling in recent months has shown drug abuse is the top concern among voters there. Nbc News National correspondent kate snow talks with a family looking for answers from the candidates. Reporter on a cold thursday night in New Hampshire, Susan Allen Samuel and her son joe find their seats at a Jeb Bush Campaign event, driven here by one dominating issue. Who would think that their child would stick a needle in their arm. Six years, overdosing at least three times. Thats three times i ended up in the hospital, probably overdosed more than that. So you live every night in fear. I was afraid to leave my home. Reporter their home is londonderry, an idyllic new england small town, but if you start asking around at janies cafe, youll find out quickly almost everyone here knows someone struggling with addiction. Owner janie turk had to fire a cook recently. Heroin is everywhere. I remind these kids, that you know, addiction, you fight that for the rest of reporter at the londonerry Fire Department last year overdoses, almost three times more than the year before. If i saw one or two a year, that was a upwards of one almost every shift there is definitely a problem. Reporter now clean for two years and a heroin almost every week. All of his closest friends from high school are dead. I can see that thats hard. Just losing people that, you know, its its completely preventible. Reporter finding treatment in New Hampshire can take six weeks or more. Its why susan and joe drove to Hillary Clintons event the next night. What do you want to hear from each and every one of them . I want to hear that they are going to do something thats going something thats going to provide treatment, and i know that we have so many other things going on in this world, but whats going on in our community is a war, too. Were losing our kids. Reporter a war in the small towns of New Hampshire and beyond that they want the candidates to see. Kate snow, nbc news, londonderry, New Hampshire. When we come back, a rare sighting finally caught on video. When we c moderate to severe Crohns Disease is tough, but ive managed. Except that managing my symptoms was all i was doing. And when i finally told my doctor, have tried other medication