might remember back in the 1970s. we've got the drought and water readministrations. what's next? >> there's something everywhere. >> all right. "nbc nightly news" is next. see you at 6:00. good night. on this sunday night, the mystery of flight 370. tonight, as 25 countries search and investigate, new details about the duration and path of the flight, and what they're learning about the pilots, while the anguish grows deeper for loved ones still waiting for answers. breaking away. today's landslide vote in ukraine'crimea region to join russia. but will it stop there? tonight, gaming russia's next move. surviving a tornado. ten months after that awful day in moore, oklahoma, a mother's mission to help give children at least a better chance when a tornado strikes. and music milestone. we're inside the grand ole opry house on its 40th anniversary as the legends of country music come home.

>> announcer: from nbc news world headquarters in new york, this is "nbc nightly news" with lester holt. >> good evening. one plane, 25 countries now searching for it, and hundreds of theories have so far added up to zero in the hunt for malaysia airlines flight 370, though we know a lot more about this flight than we did go into the weekend. the lengths that someone inside that cockpit went to render that plane virtually stealth, the direction it took, and about the pilots themselves, whose lives are being examined in close detail by investigators who are now working what is officially a crime mystery. let's get more of our expanded

coverage of this crime drama. nbc's tom costello starts us off tonight. tom, what are they doing to find this airplane? >> reporter: investigators have now re-enacted in a simulator what little they know of flight 370's path and have asked our countries to recover sensitive radar data, looking at the plane's path. meanwhile, they're looking at the backgrounds of everybody on board, with special attention to the cockpit crew, when it's clear that someone disabled the communication systems, said good night to controllers and then took the plane off course. the search in the waters off malaysia and thailand may only be a formality at this point, with satellite data suggesting flight 370 flew up to seven hours after its last-known point of contact in the strait of malacca. two wide satellite arcs show the potential direction of travel. if it went south, it likely headed deep into the vastness of the indian ocean, not covered by radar. if it went north, it could be anywhere from burma, bangladesh, kazakhstan to uzbekistan. so far, five countries, including india and pakistan, say their radars did not pick up the plane. >> we're looking at large tracts

we're crossing 11 countries as well as deep and remote ocean. >> reporter: police have visited the homes of zaharie shah and fariq hamid. investigators have dismantled the sophisticated flight simulator from captain shah's home, searching for any evidence he might have practiced for a flight diversion. >> we had to dismantle it from the room and had to assemble it at our office. and we are getting experts to look at it now. >> reporter: one friend of captain shah's is quoted as saying he is not a terrorist. meanwhile, the indian navy is pulling back, suspended its search, though the "uss kidd" destroyer continues searching a massive body of water along with anti-submarine aircraft from the bay of bengal to malaysia. >> just to give you some context as to the size of that area, if

you superimposed a picture of the united states in this area between india and malaysia, it would almost be like looking for one person somewhere between new york and california. >> reporter: but ten days since flight 370 disappeared, veteran investigators now say it's possible the plane and its passengers may never be found. >> it may be that somewhere down the road, a month from now, three months from now, a year from now, there may be debris that washes up on the beach some place that will be identifying the airplane. but we will never be able to track it back to find the actual debris site if it's in deep ocean. >> reporter: yeah, making it even more challenging, the indian ocean is the third's deepest and ocean currents can shift every day. also, the underwater pingers on the black boxes only have 30 days of battery life, which means a third of the battery life has been used up. lester? >> all right, tom. and we're joined by greg fife, a former investigator from the national transportation and

safety board. you saw him a moment ago. if these don't show any hints of the aircraft, do you become more pessimistic about the fate of finding this flight? >> i become more pessimistic about the northern trek. it looks now like they'll shift the assets more south now and start to expand that southerly track and their search there. they've included the land that borders that southerly track of the indian ocean. so, again, it will be a daunting task to cover that much territory. >> i look at that graphic. that's a big, big ocean there. is there any way to narrow it down? if you say to yourself, okay, it went to the south, can they narrow that band leading south? >> i think the biggest thing, lester, is the mathematicians that are working with whatever radar and satellite data is left to try and dissect, to hone down those last acar pings, to see if they can't get those pings -- these ping sites more focused. that's about the only thing. other than that, it's just going

to be what they've been doing, splitting that area up in grids and trying to accomplish the mission of searching it with both land and sea assets. >> all right. greg fife and tom costello, thanks to both of you. for the families of those on board of flight 370, many of them chinese, the last nine days have gone from anguish to anger, from frustration to despair. nbc's annabelle roberts has more on their long wait and difficult wait. >> reporter: if you push our limits, he shouts, there will be consequences. these men and women have been waiting nine long days for news of their loved ones. at a meeting in beijing with malaysian airlines representatives, family and friends were furious about the slow drip of information. we're all suffering so much and we're extremely angry, he says. the mother of one passenger is exhausted. her son was on his way home

after four months working in singapore. i cannot sleep. i cannot eat, his father says. earlier in the week, emotions were raw. 153 passengers are chinese. it's the not knowing, they say, that's so hard to bear. confirmation the plane's communications were switched off deliberately has given hope to the family of paul weeks, an engineer from new zealand. >> i also find it scary as well. if someone has deliberately taken this plane, they've taken it for a reason and i think we know that oftentimes, that's not good. >> reporter: they know the massive expansion of the search area means investigators are nowhere near telling them what's happened to their loved ones, but yet, they wait. annabelle roberts, nbc news, london. to our other big story in ukraine, where the voting is over tonight in the pro-russia crimean region with what appears to be overwhelming support by the people there for breaking from ukraine and joining russia. now the response in the form of

sanctions against russia by the u.s. and europe could come as early as tomorrow. our chief foreign correspondent, richard engel, is in crimea's capital tonight. richard, what's the scene there? >> reporter: good evening, lester. there's a party-like atmosphere here tonight. people have been singing russian songs. there have been fireworks. washington threatened sanctions. much of the world says it won't recognize this referendum, but still, it went ahead. russia took crimea by force. today's vote was just about the paperwork. the russian troops don't show their faces or wear insignia on their uniforms, but they're everywhere. the russian armored vehicles outside polling stations showed how moscow wanted this vote to go. few countries accept the legitimacy of today's vote held in schools across crimea. respected international election monitors weren't allowed to come. one thing that is transparent about this vote is the ballot

box, and so far, all the votes we've seen have been for joining up with russia. russia has popular support here. so how did you vote? >> i vote for russia simply because crimea has always been russian. >> reporter: for crimea's deputy prime minister, it's a done deal. so, if i want to come back here, i'm going to need a russian visa? >> yes, you should do it. >> reporter: get a russian visa? >> yes, with russian visa. >> reporter: because ukrainian visa won't be enough? >> yes. crimea is not ukraine. crimea will be a russian federation. >> reporter: some say the vote wasn't exactly free or fair. dennis showed us the billboard outside his apartment building where someone put up this poster, warning neighbors, a traitor is living among you. activists like you have been beaten here, intimidated certainly. do you think you lost? did russia win? >> translator: crimea lost and so did ukraine, but i'll

continue to fight against putin's regime, he said.crimea so did ukraine, but i'll continue to fight against putin's regime, he said. but tonight, celebrations are already under way. a welcome to russia party for crimea. what's next, lester? next week, the russian parliament will very likely vote to annex crimea. then the currency here will be slowly phased out and replaced with the russian ruble and this province will become the newest part of russia. >> president obama and president putin spoke earlier today, president obama saying the u.s. will never recognize this vote. so, what does that mean to russia? do they care really? can the u.s. really do anything to change this direction now? >> reporter: this is a fait accompli. i don't think this will change any time soon. what the conversations could mean, however, is stopping russia from going any further.

there are politicians in this region who say that crimea is only the first step, that this region today voted to join up with russia and eastern ukraine will be next. sanctions and a strong position from washington could prevent that. >> richard engel tonight, thank you. not far from ukraine, in sochi, russia, the closing ceremony of the paralympic games was held tonight. the glittering ceremony was attended by president putin. russia cleaned up with 80 medals, ukraine came in second with 25 and the u.s. was third, with a total of 18 medals. a big part of this country has been dealing with rough weather this weekend. and tonight, there is everything from severe thunderstorms in the southeast and more snow and ice from the midwest to the midatlantic. we get more tonight from nbc's ron mott. >> reporter: in texas, hail the size of golf balls made a mess and a racket, forcing drivers to seek shelter from falling ice. in alabama, a dozen campers had to be rescued after their

campground flooded. and officials will determine if a collapsed strip mall near the border with florida was hit by a tornado. in the beleaguered midwest, a balmy saturday in kansas city gave way to a frosty sunday. most everywhere, spring can't be sprung fast enough. >> i'm done. i'm absolutely done with the snow. >> it's too much. >> reporter: this winter of discomfort and discontent is leaving a lasting mark. seven states suffered through top ten coldest seasons on record and the bill to keep warm, costly. propane expected up 54% on average nationwide compared to a year ago, totaling more than $2,200 for families in the midwest. other energy sources more expensive as well. >> folks in the midwest and the east have experienced a cold and snowy winter, which is really unusual compared to the 21st century. but the real climate issue we face is out in the west and that's lack of water, drought and lack of snowpack out there. >> reporter: back east, even more snow ahead tonight and

tomorrow in places like the nation's capital, just four days from the official start of spring. >> a swath from the mountains to the big cities to the coast. take a look at philadelphia, one to three inches, impact on the morning commute. same goes for washington, as much as six inches of snow there. >> reporter: changing seasons roughly. ron mott, nbc news, atlanta. there were tributes today to david brenner, the comedian who found so much in everyday life for us to laugh about and was best known for his appearances on nbc's "tonight show." 158 of them. nbc's joe friar has more tonight on the life of a very funny man. >> reporter: david brenner's legendary comedy career spanned more than four decades. >> i can never figure out, how come a dog always confuses my leg for his girlfriend? >> reporter: but that career came lasting only a few months. >> i was always doing a lark. turned out to be a very long lark. >> reporter: his big break came when he debuted on "the tonight show" with johnny carson.

>> this is his first appearance on television. he's very clever, somewhat warped. >> reporter: at the time, brenner had three bucks to his name and didn't think he would stay in comedy. but that night, he killed it. >> and did you ever notice that the same guy works in every gasoline station in america? it's that character with the hunting cap with the earmuffs. everything i've made above $3 in all these years was due to johnny carson. >> reporter: he briefly hosted his own late night program, "night life" and was a regular on "hollywood squares." >> david brenner. >> reporter: brenner never lost his sense of humor, even while battling cancer. his final request at age 78, that $100 in small bills be placed in his left sock, he said just in case tipping is recommended where i'm going. joe friar, nbc news, los angeles. when "nbc nightly news" continues on this sunday, as tornado season begins, one mother's mission to help protect the children. and later, making a difference by helping families in need stay warm.

last year's devastating tornado in moore, oklahoma, put a new spotlight on the lack of underground shelters, especially at schools.

while building more shelters is a long-term goal, one mother realized there's something that can be done now to better protect children. we get the story tonight from nbc's gabe gutierrez. >> reporter: these are what have consumed jennifer brumley for nearly 10 months. >> how do you thank a teacher who saved your child's life? the least we can do is give them better resources. >> this is terrible. >> reporter: when an ef-5 tornado tore through moore, oklahoma, last year, killing 25 people, including seven children. her son, a third grader at a flattened briarwood elementary barely survived. >> one of the comments my son made was that he only had a dictionary to protect his head and that scared him. >> reporter: so she launched into action, raising money and organizing volunteers. >> research we did indicates you would cut the risk of serious injury and death just about in half if not more by having a helmet on, versus not. >> reporter: the group raised enough money to purchase 34,000 helmets, enough for every student and employee at moore public schools. >> it's an added layer of protection for the kids.

if it's needed, it's there. and we hope and pray to god they never need it. >> reporter: on the helmets, reflective tape to help first responders fine trapped kids. >> if we can save one kid's head, one head trauma, we're saved a life. >> reporter: still some say helmets are a good first step, but not enough. would a helmet have saved your son? >> no. >> reporter: dani legg lost her son. >> it's a no-brainer. we need shelters in schools and we've got to figure out a way to make it happen. >> we would love to have a storm shelter in every school that could hold all of the students for each building. >> reporter: the question is how to pay for it. >> it is. it's an expensive proposition. >> reporter: so for now, these helmets offer parents like jennifer brumley more peace of mind. >> the long-term solution is beyond my scope, but this was something we could do this spring. >> reporter: a spring they hope

will be a much quieter season. gabe gutierrez, moore, oklahoma. we're back with a big celebration that brought out some legends of country music.

the grand ole opry has been the spiritual home of country music for years, launching some of the biggest names in the business and bringing us the world's longest-running radio show. the opry itself has had a lot of homes along the way. last night in nashville, a celebration for the ages as the current opry house turned 40. it was an historic moment, captured on the grandest of stages, a who's who of musical giants and aspiring artists, gathered to celebrate the home of country music. ♪ came down from birmingham on the wabash cannonball ♪ >> we're thrilled to be able to

celebrate four decades and if these walls could talk, an incredible story it would tell. ♪ my pappy used to tan my hide >> reporter: a story of legends. >> there's not another place like the grand ole opry. >> reporter: it's the world's longest running live radio show dating back to 1925. this is the opry's sixth home. it moved here from the famed ryman auditorium in 1974. >> it's the first venue that was built specifically for the grand ole opry. >> reporter: on this day 40 years ago, the opry house opened with performances led by then president nixon. >> he played the piano. of course, paul anka was good with the yo-yo. they kind of went together. >> reporter: in the last four decades, country music has exploded and some of its brightest stars got their start here. >> i was very nervous and then once i got out there, it was somehow not a place to be nervous. >> reporter: in 2010, the opry house suffered severe damage from the nashville floods, forcing the show to temporarily relocate.

the water was this high? >> yeah. the water, 46 inches. >> reporter: five months later, it was back in business. and i had a chance to see for myself just what makes this place so special. >> who's going on in here? >> ricky scaggs. >> oh, yeah. my goodness. can we go in? ♪ >> we're all family here. we all feel connected. >> reporter: this weekend, some members of that family reunited to mark this milestone. look for another big celebration next year when the opry, as an institution, reaches its 90th birthday. we're back in a moment with how neighbors are helping neighbors get through a brutal winter and are making a difference.

just about everyone who has to buy gas or oil to heat their homes is painfully aware of this winter's added cost for coal. the same is true for wood. one community is helping to ease the pain for those who find it hard to make ends meet. rehema ellis on how it's making a difference. >> reporter: new hampshire, famous for its natural beauty, and for long, cold winters. around hopkinton, wood stoves help, but just as heating oil costs are rising, so are wood prices. >> hello, ladies. >> reporter: for some, like retired nurse rosalee smith, barely making ends meet, it's a struggle just to stay warm. fortunately, rosalee can take a

voucher showing her need to get free wood from the town wood bank. it's like a food pantry. mary congoran started the wood for warmth program eight years ago when the nation's economy was headed for the deep freeze and her neighbors were hurting. >> i just looked out my window one day and said, you know, i'm surrounded by trees. there's got to be a way to get wood to people. >> reporter: in the past two years, she's raised over $36,000 to buy wood for more than 40 homes. it's donated, cut, stacked and delivered by volunteers like peter powers. his son, sean, an iraq war veteran and police officer, died in a motorcycle accident. you the program is named for sean. >> i was so honored that they named the wood bank after my son. it's the first thing i thought of, i'll help you. >> reporter: but mary had to convince many neighbors to accept the help. >> sometimes i would have to tell a little fib and say, you

know, i've got all this extra wood and it's just going to go to waste. so, you can help me out by taking a little bit of wood. >> reporter: at 66, rosalee is grateful, but still wants to do for herself. >> i like being able to say it's my place. i'm heating it with my effort, with some help from mary and the town. >> reporter: making a difference so independent new englanders can stay warm and stay proud. rehema ellis, nbc news, hopkinton, new hampshire. that's "nbc nightly news" for this sunday. i'm lester holt reporting from new york. for all of us here at nbc news, good night.

tonight a man is in the hospital after being hit while in a crosswalk. it's prompting questions about safety on san francisco streets. plus a house in mountainview went up in flames and good samaritans stepped up to help. we'll show you how, and more countries are called in to help search for that missing plane. good evening, and thanks for joining us. i'm diane dwyer. terry mcsweeney is off tonight. a man in his 60s is inn critical condition tonight after being hit by a tour bus in san francisco. the accident happened at the intersection of seventh and mission. it comes amid growing concerns about pedestrian safety in the city, and