Discovery that could kill disease and locals have known about it for hundreds of years. This is nbc nightly news with kate snow. Good evening. In nebraska tonight they are bracing for more historic high water with record snowfall in february and then rainfall this past week and now temperatures in the 50s melting off that snow. Rivers are cresting. 11 million americans tonight face the threat of flooding from nebraska through other parts of the midwest down the Mississippi Valley and all of the way to the south. And landed. Really cold, and many now in shelters indefinitely. It looks like an ocean everywhere. Nebraskas governor declared states of emergency and dozens of counties and tribal lands describing the damage as unbelievable devastation. In nebraska, the 90yearold spencer dam was destroyed sending floodwaters into nearby towns with bridges washed away, Emergency Responders went in on both to help. There is an entrance, Paradise Lakes insane. The rising waters are blamed for at least two deaths in nebraska, and one in iowa. A farmer killed trying to save a trapped motorist. Another person refused to evacuate and a driver died after going around a barricade. Several communities in wisconsin and minnesota also dealing with flood emergencies. The Missouri River overflowing to record levels as residents downstream fear the threat isnt over. And while the water is starting to recede in some parts of valley, nebraska, the flood here is very high and tuesday could trigger another set of problems. Kathy park out there for us. Kathy, thank you. As survivors of the terror attack in new zealand begin to share their stories we are learning more now about both the unspeakable horror and the incredible bravery of that day. Nbcs Miguel Almaguer is there reporter with hef hearts this nation is grieving, now the loss of another soul. A 50th victim has been found after fridays mass shooting in two mosques. My dad took a built for me. Ali adid survived at the al noor mosque. His father sammy is in serious condition. He said take care of your mother and your brothers and sisters. Reporter police say the terror came at the hands of Brenton Tarrant who live streamed the massacre. Authorities saying they received a racist manifesto nine minutes before the gun fire began. I saw him yelling and i saw the shotgun in the hands. Abdul aziz found an empty gun left behind by the shooter and chased him away from the weapon preventing further bloodshed. The gun i had in my hand was the shotgun, and i throw at him at his window. The suspect was arrd blocks away. His grandmother said he showed no sign of extremism. Were all gob smacked. We dont know what to think. New zealands Prime Minister comforting families, and is now vowing to change firearm legislation. We cannot be deterred from the work that we need to do on our gun laws in new zealand. Tonight, dozens remain hospitalized, wasim and his 4yearold daughter among those shot multiple times. Please pray for my son, for me and for my daughter. A country torn apart by hate, now promising to come together with hope. With the death toll at 50 not far from here, dozens remain hospitalized including a 2yearold child. We also know that many of the victims bodies remain inside those two mosques that became crime scenes. They are slowly being released to their families. Kate . So tough. Miguel Miguel Almaguer, over there, thankpany and other social media platforms are trying to remove allome cases e the massacre, but as nbcs morgan tells us its an uphill battle. Reporter an act of violence made to go viral. This frame of 17 minutes of murder streamed to facebook live. Condemnations came quickly. Facebook, twitter and google all promising to remove the video. Youtube terminating any account that shared it. Tonight the footage lives on, almost impossible to regulate. They know this is a problem. They have the technology to stop it, but they have to have the willingness. Reporter facebook responding in the first 24 hours we removed about 1. 5 million videos of the attack globally of which 1. 2 million were blocked and upload removing any praise or support of the crime. The question how to contain the online chaos. This is a new, very, very im. I donth obvious or easy answer. Tonight the new Zealand Government taking a legal stand against the video, anyone who shares any version of that footage is in violation of local law. Kate . Morgan, thank you. In ethiopia today a government minister says it appears the crash of a boeing jet last sunday had similarities to another crash of the same p october. Authorities are beginning to analyze the black box data from last weeks disaster as the country paused today to mourn. Heres nbcs morgan radford. Reporter thousands lined the streets today, the victims of a nation in mourning. Remains of the victims of the doomed ethiopian flight wont be recovered for month, but news today that the black boxes pulled from the field where t ce yielding information for investigators. The ethiopian transport minister says preliminary results show clear similarities with an earlier disaster. A lion air flight that went down just months ago in indonesia. In that case, investigators say the boeing plane crashed when an Automated System meant to keep the 737 max 8 aircraft from stalling actually caused the plane to crash into the sea. This data will be carefully analyzed and it will tell the tale of what happened. The faa today saying the u. S. Government has not yet validated the data. A prelinary rort is expected to be released within 30 days. Morgan radford, nbc news. In syria, the final battle against isis has dragged on for weeks now as the militants put up strong resistance and some even resorting to suicide attacks at the same time other isis fighters are giving themselves up. Nbcs matt bradley witnessed one of those attacks. It not going down without a s co fight. For two months the u. S. Led coalition has battered its last holdout from the air. As americanbacked Syrian Democratic forces, the sdf fight from the ground. Reporter they tell us there are many, many more left ins including women and children. Reporter more than 3,000 surrendered the past few days and many badly injured. We spoke with adnan, an sdf commander. Were going to the first point where the fighters reached and after that, its just isis. But our interview was cut short. Go, go, go, go, go. Go, go we have to get out of here. Our interview was interrupted. It looks like there was a counterattack by isis. As we race to safety, sdf fighters carried a young boy and girl seriously injured to a field hospital. When we returned afrin had taken up a sniper position himself. There are conflicting reports and the commanderd suicide bomb pretended to surrender and to instead. The two injured children, the son and daughter of one of the women. The young boy survived, but the girl died. Their mother willing to kill her own children for her dying cause. Matt bradley, nbc news, bagu, syria. Residents of los angeles had a scare this morning after leaking gas le leaking gasoline exploded. A black cloud could be seen for miles. The explosion so strong it sent Manhole Covers flying. Two people in the house were injured by the blast. The democratic nominees were out stumping for votes on this st. Patricks day, and it is a packed feel of 13 and could be getting more crowded soon. Kelly odonnell has that and has our report. Reporter on this st. Patricks day, iowa holds its own electoral pot of g democrats. Happy sairt. Patricks day. G it. Klobuchar from minneso i will sign us back into the on day one as your President InternationalClimate Change agreement. But first comes the party electability test. I will do anything to win. For beto orourke. I really feel the call of this moment. Reporter that test is about expanding the map. I want wisconsin to know that im here. Reporter a state democrats still grimace about losing in 2016. When we dont show up we get what we deserve and that is to lose. Reporter the path to the nomination may be paved with selfies. How is everybody . Reporter and voters sampling the broad field. I think we need fresh face and the young. I like the youth. I like the youth ideas. Reporter today, after exploring a run for several weeks, Kristen Gillibrand made her entry on video. We need a leader who makes big. Bold. Brave. Tripped his way cred. I have the most progressive record of anybody running of anybody who would run. Reporter and running at his own pace. Today the president who typically goes to church on christian holidays attended st. Joes episcopal with the first lady, the first regular sunday service he has attended in office. The president s Upcoming Campaign schedule is mixed in with his official duties. Hell be attending a fundraiser this week in canton, ohio, and then the following week hes announced a rally in grand rapids. The Campaign Says that will be his 18th visit to michigan and it certainly is a sign, kate, that both parties will give a lot of attention tokate . Its goio be a long number of month, kelly odonnell, tha so much. Police have a suspect in custody tonight after the murder of a reputed new york crime boss. Francesco cali. Police say the suspect anthony carmel on backed his pickup truck into calis car outside his home on new yorks Staten Island and when cali, the reputed boss of the gambino crime family came out to inspect the damage carmelo then shot him ten times. At this point, is does not appear the killing was mob related. Now to a controversy that has environmentalists and the Energy Industry making noise. The Trump Administration has approved seismic testing along the eastern seaboard, allowing companies to use sound waves to search for oil and gas, but conservationists say the tests could harm sea life and theyre challenging them in court. Nbcs ann thompson has more. The waters of the atlantic, the side of a legal and political storm over the sound underneath. Seismic testing to find oil and gas. Cunningham tried to replicate the test. Was that disruptive, mr. Oliver . It was irritating, but i didnt find it particularl reporter c deserve sounddependent marine life. Whales rely on sound to communicate, fight mate, find food and avoid predators. Reporter the Trump Administration has approved seismic testing from delaware t seconds that penetrate the seabed, the reflected pulses create a map of the oil and gas deposits and more. How far can the sounds travel . A thousand to 2,000 miles. The Senior Science adviser at the new england aquarium. How loud is it . Imagine youre at the end of laguardias runway and a jet flies every 16 seconds at 100 feet. Reporter most at risk, the e. 3 endangered north Atlantic Seismic is adding one very big stressful impact on top of everything else, and this tipping point. . To the point where they disappear altogether . Its possible. The government concedes there could be impact, but not enough to kill or seriously injure marine life. Assurances, coo assurances echoed by the oil industry. Weve been coexisting with marine ecosystems for years and we just havent seen adverse impacts. B the states fear testing could lead to exploratory drilling and another deepwater horizon disaster, threatening the fishing and tourist Industries Worth billions. Air gun blasting is the loudest, economically and environmentally destrktive noise that humans will never hear. Im saying stop it bipartisan opposition turning to the courts hoping theyll listen. Ann thompson, nbc news, new york. Still ahead tonight, we go to the green hills of Northern Ireland where some think the soil could help cure what ails us. Also, he broke barriers serving as a navy s. E. A. L. And at 82 years old hes still giving back. Incredible discovery in Northern Ireland. Its about the soil there, and how its used as an ancient folk cure can actually help modern medicine fight infections. Our chief medical correspondent dr. Johnakes a urgent warning tonight about the alarming rise in deadly germs resistant to antibiotics. Every year in the United States 23,000 people at least die from an antibioticresistant infection. Thats like a jumbo jet crashing every week. Reporter these germs are called super bugs and Scientists Say if new antibiotics are not could be at risk. Microbiologist jerry quinn believes the answer may be here, Northern Ireland. A land where the Rolling Green hills are dotted in sheep and the drink of choice is a pint of ginnes. You have a hint that something is going on here. Yeah. Around this area there is still ethnopharmacology which is local medicine and theyve been here for thousands of years. One of those folk cures passed down from generation toe possesses healing powers . You take the soil, a s a little bag. And you say a series of set handkerchief, maybe sometimes in prayers. And the a faith cure to cure all illnesses. And when there are thousands of years, there is a basis behind it and theres some reason it works that we dont know about. We can look at it and say its superstition and look closely aeeat quinn tested the soil. What he found in the mineralrich lime stone was stunning. New strands of back teteria nev before seen. He wondered, could they fight or kill germs . The result was shocking. It was able to kill the worlds most deadly super bugs. Could this be the cure for antibiotic resistance . Its part of the answer. The next step, testing it in humans and perhaps this ancient irish secret could be the cure to whats ailing us now. Dr. John torres, nbc news, northern moment some scenes from across america and the world where people today celebrated the feast of st. Patrick, otherwise known as st. Patricks day. There were parades. There was green beer and there were green rivers. A sign of spring now with truly stunning pictures from southern california. Its called the super bloom following weeks of rain, california has finally emerged from its drought and wild flowers have begun to blossom. Wednesday, by the way, marks the official start ofprg. From flowers to fires. An austrian town has built the worlds tallest bonfire. It was 200 feet high and it burned to the ground in less than half an hour. Really hoping someone brought some marshmallows. When we come back, three tours in vietnam, countless classified missions and well tell you the story of a trailblazing navy s. E. A. L. Who is still serving his country. When bill goins became the first plaque navy s. E. A. L. He didnt know he was a trail blazer and now over 80 this veteran is still serving, inspiring a wheel new generation. Nbcs jeff bennett went to virginia and met up with an american hero. Retired navy master chief billns new encouraging students of color to consider becoming navy s. E. A. L. S. The training is actually it takes about a year. Reporter the 82yearold nearly missed his shot of joining the elite force because of an accident in his high school woodworking class. When i went to get the exam and the guy said that part of my finger wasssing, he said thats your trigger finger. I said no, im lefthanded. Were you . Not really. I wasnt 100 . That obstacle, among the many goin faced in becoming the first africanamerican navy s. E. A. L. Over his 32year career, goins carried out classified missions all over the world including three combat tours in vietnam. His favorite part of the job, freefall parachuting. I was dumb and young then. I couldnt wait to get back up and do it again. What does it feel like to be a trailblazer . It was way into my career before i realized i was the first africanamerican navy s. E. A. L. Reporter few people ofhave duty navy s. E. A. L. S, just over 1 areican nearly 9 are hispanic. A Diverse Group with different ways of thinking hps battlefield. Reporter but goins did inspire the first black officer to command a s. E. A. L. Team. His identity shielded for security reasons. He allowed me to focus on training as opposed to focusing on being the first. What reason reporter bill goins, long retired, but still serving. If he can do it, anybody can do it. Reporter a Pioneering Navy s. E. A. L. , passing on an enduring legacy. Jeff bennett, nbc news, virginia beach, virginia. And that is nbc nightly news on this sunday. Lester holt will be with you tomorrow. Im kate snow. From all of us at nbc news, have a great night. The news at six t now. Good evening and thanks for joining us. I m vicky nguyen. And i m garvin thomas, in for terry mcsweeney. The news at 6 starts right now. Thank you for joining us. We are learning more about the young driver found dead in the car on the contra costa highway, that car full of bullet holes. Nbc laura sambol has more on the investigation. Laura. Reporter this ishe the crash happened just before 2 30 yesterday. Look behind me. Im at the willow road offramp and you can see the cones rail. That guard rail was ripped apart and lives torn apart. She was really a charming girl, bright