not. >> we have more showers coming in this evening. this weekend is trending drier. thank you for joining us at 5:00. on this thursday night, the state of emergency as neighborhoods are flattened by a ferocious of tornadoes as the storm shelters are no match for the flash floods and tonight al roker is here to tell us the worse is yet to come. the fbi warning hours before that terrorist attack in texas. the urgent bulletin sent to local police about one of the shooters. what did they know. pollen tsunami suddenly hitting very hard. why doctors say allergy season is coming all at once and what you can do to survive it. and tom brokaw opens up about a very personal battle with cancer. how a devastating diagnosis changed his life and his family and how he's doing now. "nightly news" begins right now.

from nbc news world headquarters, this is nbc "nightly news." reporting tonight, good evening. >> we've been keeping a close eye on tornado warnings and severe thunderstorm watches popping up tonight in kansas texas and oklahoma, all this on the heels that have wild tornado outbreak that unleashed some 50 twisters across four states yesterday, including this big one in kansas. one of the biggest and most damaging within half mile wide twister we watched live near oklahoma city as we came on the air here in the east last night. that tornado killed at least one person and injured dozens and left more than -- in a moment al roker tells us about a larger outbreak as we head into the weekend but first nbc's janet shamlian from already hard head bridge creek, oklahoma. >> now you're getting clear funnel contact to the ground. >> reporter: a massive tornado half a mile wide, tearing through oklahoma. >> i got trees coming

down on me and power flashes. i've got to back out of here. >> reporter: our nbc station kfor in the middle of it just south of oklahoma city in tornado-prone norman. part of a widespread outbreak with millions in the path of danger. >> a large multiple vortex tornado on the ground here south of lincoln, kansas. >> reporter: eerie sounds of sirens in oklahoma nebraska kansas and texas. >> we have lots of debris on the ground here. >> reporter: at least 50 tornadoes across the four states. >> the destruction is a lot more serious and worse than i imagined. >> in oklahoma city the entire airport was evacuated to an underground shelter. warnings blared across the university of oklahoma campus outside driving rain hail and dangerous flash flooding left cars underwater. a wall was hipd off a hotel and roads buckled under pressure. one woman died when her storm shelter flooded. katie and josh thought it would happen to them. their underground shelter was filling

fast, but with the overhead door covered in debris they were trapped. >> i think that was probably the most scary thing is when you don't know what to tell your kids. >> reporter: a neighbor heard their screams and rescued them. >> such a relief, you know, that somebody was out there looking out for us. >> reporter: oklahoma governor mary fallon today. >> we saved lives because we took action early and, you know we have a good system in oklahoma. >> reporter: tonight with more storms in the forecast it's a race against time for those already hard hit. families like the longus focusing instead and having been grateful for what they have. >> our kids are safe. we can rebuild. >> reporter: many families are dealing with no roofs over their head also more storms are upon us and it's worth noting that this is fairly new construction because this entire neighborhood was flattened in this very same spot by a tornado in the past. lester. janet shamlian. as we set off at the top the outlook is for

even more tornadoes as we head into the mother's day weekend. al roker is here to break it down for us. al, what are we looking at? >> more strong storms. not a tornado outbreak going on right now and to give you a sense of how strong the storms are. look at the video in why enough the the last hour. this is i-25 near colorado springs. they got about 4 inches of hail. that's how intense these storms are. rivers of hail right now. it's all but come to a standstill on i-25. as we look at the radar, you can see there's a pretty good line of thunderstorms. we've got thunderstorm watches in effect until midnight central time and oklahoma city down into dallas texas. we're watching lines of thunderstorms n.fact, with some of these storms we've seen near norman oklahoma. one gymnasium actually collapsed the room because of all the heavy room. there's almost 18 million people. a few tornadoes possible from oklahoma city down to dallas.

now we have a strong risk from wichita, oklahoma city and some of these tornadoes could be very strong. 18 to 19 million people and then we move into saturday. again, that strong -- this is the day we are most concerned about lester, from wichita, falls into oklahoma. some of these tornadoes could be the long track tornadoes and the strong tornadoes that could cause major damage. >> all right. al roker, al thanks very much. there are stunning new revelations about that terrorist attack at an anti-islamist event in texas. the fbi director revealing tonight that the feds sent a bulletin to local police warning them about one of the men who would open fire just hours later. our justice correspondent pete williams has late details. >> reporter: just three hours before sunday's shooting attack in garland, texas texas, the police sent a secure electronic message with eltoncism sob's number and car license number. the fbi acted as soon

as it developed information that he was interested in going there but had no reason he wanted to attack it or even that he left phoenix, and there's no indication the fbi says that the officer who ended up shooting simpson and nadir soofi ever saw that bulletin. garland police tonight declined to say what they did in response to the information. the fbi says the latest plot shows how radically terror recruitment has changed, from a time when those interested in jihad had to seek out websites by the fbi could monitor to now when isis pushes out its messages on social media, urging anyone who will listen to stage attacks wherever they are. the fbi director james comey today told reporters i know there are other elton simpsons out there. he says hundreds of people in the u.s. maybe thousands, are following jihadist social media, and the fbi is investigating hundreds of potential home-grown extremists with cases open in every state. it's a subject that has congress worried, too. >> isis is a large organization. it can afford to have 2,000 people who tweet 150 times every day.

it can afford to have a ratio of two or three recruiters to every recruit. >> reporter: and comey says the discussions that start on twitter often go to enkriptded forms that the government cannot read. the fbi is so concerned about this and an increase in isis efforts to get something going in the u.s. that tomorrow comey and the homeland security secretary je he johnons will take this message to the police in a secure conference. >> pete williams thank you. tonight millions in the uk are staying up late to hear the results of a cliffhanger election with exit polls showing prime minister david cameron's conservative party ahead of the opposition labor party but without a big enough lead to declare an outright victory. cameron will have to form a coalition in order to stay in power and returning to ten downing street. one day after the nfl's independent report on deflategate

found new england quarterback tom brady was probably at least generally aware footballs were deflated in a playoff game, brady's agent came to his defense as the sports world waits to find out what penalty, if any, brady might face. we get the late forest nbc's ron mott. >> it's a fine line between cheating and gamesmanship. >> reporter: on sports talk radio tom brady topic one, callers sounding off including the reporter who broke deflate gait. >> i think it's abject cheating absolutely. >> reporter: brady has thrived under pressure throughout his career but this isn't a pass rush. today the reigning super bowl's champion blasted the wells report as a significant and terrible disappointment which omitted nearly all of tom's testimony and key facts. >> this is one of the greatest quarterbacks not just of this generation but of the history of the game, and he's a cheater. >> reporter: commissioner roger goodell said the nfl will vigorously protect the integrity of the game. its policies stating that failure to cooperate in an investigation shall be considered conduct detrimental to the league and subject to

discipline. brady seen here during a game last december refused to turn over his cell phone or any text messages and e-mails, not helpful, said the lead investigator ted wells. >> we don't have a smoking gun and one of the reasons we don't have a smoking gun is because quarterback tom brady refused to turn over his text messages and e-mails, and that creates a separate problem for bradiy. >> on social media, a different kind of firing squad. one twitter writing cheat and lie and you get mvp and super bowl ring. true loser. wrote another, tom brady american hero and role model cheater, cheater, pumpkin eater. one supporter called the report a joke. haters going to haircuts hate, hate, #lovefortombrady . now tonight tom brady arrived at salem state university north of boston for a previously schedule speaking engagement. cameras are allowed inside but must shut down ten minutes after the program starts. no word on whether the quarterback is going to address any of this before the cameras stop rolling. lester? >> ron mott thanks. we're joined now by

our friend bob costas at yankee stadium where he's calling tonight's game. bob, a lot of conversations had today about the question of whether it was cheating come down to what would you tell a child, a 10-year-old playing pop warner cheating or some kind of a wink wink part of the game? >> reporter: well, certainly not unique to the patriots, not unique to football this. sort of thing which some view as gamesmanship has been going on for a long time, but it is a rule, and if let's say someone is offsides on a play in football. you don't say did it actually affect the play that happened on the other side of the field? you assess the penalty. so the patriots knowingly broke a rule. how important is that rule? is it as egregious at other forms of cheating? did it have the kind of impact on performance that steroid use or other forms of cheating would have? i don't think so. will tom brady just be just as great without it, yes, i do but they knowingly broke an established rule. last night, lester i told you i thought they would lose draft choices and brady would be fined but i didn't think he who is

suspended. i've rethought that. in light of the year that the nfl has had and all of the attacks on its integrity and the attacks on the commissioner roger goodell for in some cases being too soft i think if they go soft or are perceived as going soft on the glamour boy of the league tom brady and on the super bowl champions, there will be hell to pay and what will happen, i think, he'll be suspended for at least the first game which happens to be the thursday night game, the only game that the whole country watches that particular night when the super bowl champions have the honor of hosting the first game. i think we'll get at least a one-game suspension. >> an interesting take. bob costas, thanks. have a good broadcast. >> thanks. tonight, millions of americans are feeling the effects of a sudden onslaught of allergies all at once. it's being called a pollen tsunami, a spring season of misery being played ironically on the brutal winter that was. nbc eanne thompson has the report. >> reporter: spring has sprung, and so has the pollen. you can see it and hear it.

>> there we go. >> reporter: as allergy sufferers unite in misery? my eyes get really itchy and they feel a little bit swollen. >> reporter: today on this hospital rooftop in suburban chicago this doctor recorded the highest tree pollen count. >> going to be heavier in the next few weeks. >> reporter: a pollen tsunami sweeping across the country with the upper midwest and northeast getting hit worst. traverse city michigan, the most uncomfortable, but not record breaking. >> it's about as bad as it normally is. >> reporter: long snowy winter accelerated pollen production in grasses and trees. i always think of this as being the problem. >> these are not really the problem here. these have got showy flowers that we tend to notice and they are make themselves attract i have to insects to distribute their pollen for them. the ones that we need to worry about more are usually ones that are wind pollinated and they don't have

conspicuous flowers. >> reporter: sycamore and oak trees fill pollen filled clusters that send people to their doctors in search of relief. >> people need to rely on over-the-counter remedies such as styline nasal sprays eyelid wipes if the eyes are puffing, rinsing their face at night and shampooing at night to get rid of all the pollen. >> reporter: make sure you don't bring the outdoors in. anne thompson, nbc news, new york. >> there's a lot more ahead to tell you about. tom brokaw opens up for the first time about his fight with cancer. the back pain that turned out to be the battle of his life. why he's speaking out now and his message to others in the fight.

we're back now with a story about one of our own tom brokaw. of all the stories that tom has covered over the years the most personal has to be his own battle with cancer. multiple myoloma, a blood cancer. he's doing much better. the cancer is in remission. he's written a book about it. "the lucky life interrupted" talking about what he went through, what he learned, and how essential his family has been. he talked about it with our national correspondent kate snow. >> how you feeling? >> i'm actually feeling pretty good. i'm in remission. i have some back issues that i'm not happy w. i had four fractures in my spine. they were repaired. it caused me four inches of height. it really attacked my

vanity. >> how tall are you now? >> i'm now 5'9". i played basketball 6 feet. i went to 5'11" in my 50s and, bang i went down to 5'9". tough. >> in the has of nbc, tom has a nick naik name, tom the dunking horse. >> went back and survived the war. >> reporter: hardworking, tenacious and lucky in life, charmed even. then about two years ago a nagging back pain turned out to be much more. >> he looked at me and said you've got a malignancy. it's called multiple myeloma, and i said how long? he said statistically five years, but i think we can probably beat that. we're making a lot of progress with this cancer. >> did you think you might die? >> i never thought i might die. that's the conceit of an anchorman, that we can live forever, i suppose. >> he thought he could live out at his ranch. >> got up the next morning and did a really dumb thing. i went fishing. >> he ended up being

flown down to the mayo clinic and his daughter is in san francisco and she became the coordinator of his care. >> part of the reason i wrote this book is i really wanted to offer advice for families going through this about what i learn. one, get some somebody who is a friend of yours who is a physician who can interpret what they are saying. >> reporter: he also learned that cancer affects the whole family. his wife of more than 50 years meredith his three daughters and five grandkids. >> this experience they said to me brought them even closer together, but what they realize is that i'm not going to be around forever. i do think that all of us objectively understand that we are approaching the end of our lives, but subjectively it's really hard to come to grips with. >> reporter: tom's daughter sarah worried that her son archer tom's only grandson wouldn't get enough time with his

grandfather. >> only had six months with him. i want to envision you playing baseball with him and fly fishing and not knowing if that was ever going to happen. >> we've got kind of a pact that we're going to do. already had him out on the docks showing him about fly rods and he's learning how to crank a reel so we'll get there. >> reporter: you going to be around? >> i'm going to be around. you know, my last line in the book is life what next, bring it on. that's how i feel. >> reporter: kate snow, nbc news, new york. >> and tom will have much more tonight in a special hour of "dateline" at 10:00, 9:00 central. we're back in a moment with a huge surprise from stephen colbert, helping out hundreds of stunned teachers and students.

lumber liquidators stopped sales of all laminate flooring made in china after allegations that the product contained high levels of formaldehyde, a carcinogen

carcinogen. those allegations were first reported in march on "60 minutes" and since then the company has sent thousands of air testing kits to its customers. it says in those that had been analyzed 97% had formaldehyde levels that fell within guidelines set by the world health organization. a medical crisis tonight for one of the biggest music stars on the planet. sam smith who told fans on instagram today that he's about to undergo surgery to repair a hemorrhage on his vocal chords. smith says doctors tell him he should be on stage in about six to eight weeks but he's not even allowed to speak for three weeks after the operation. he grew up in south carolina and now stephen colbert is giving back to his home state in a big way. the late night host announced today he'll finance all the school projects in south carolina listed on donorschoose.org, a crowdfunding site where teachers ask for help. 2,000 projects submitted by teachers in 375 schools costing $800,000. colbert raised the money by auctioning off the desk and other

items from his show "the colbert report" which ended in december. when we come back, it's a ride of their lives. a new course they are trying to chart for young women.

while the gap may not be as wide as it

once was, a career in science is still pursued by men more men than women. so to help close the gap further, two women have started an unusual campaign pedaling their message across schools across the country. >> reporter: past the vineyards of napa valley you'll see two friends pedaling their way from san francisco, some 60 miles so far. only 3,000 miles left to go. >> it's like we're married. honestly we've like made this vow to ride our bicycles across the country together through sickness and health and through the good and the bad, like -- >> reporter: elizabeth case and rachel woods robinson met in physics class at ucla fast friends in a program dominated by guys so they are gearing this cross-country trek towards the girls. carrying more than 100 pounds of gear. >> not too bad. >> you want to try lifting it? >> no. >> reporter:

everything they need to teach pop-up classes at middle schools on their way from california to new york first up sacramento where they spring out their bikes, not those, these, mini cycles printed in 3-d and powered by the sun, built by the students. >> good job, it works. >> reporter: who learned to turn solar energy and some plastic pieces into a joyride. >> i like how i can discover new things and learn all this amazing stuff. >> reporter: teaching by example. >> be curious and realize that you're good enough. >> what's the message that you're giving to these students these girls? >> you're good enough, can you do it. >> if they can build a bicycle they can be a scientist and i think that's a beautiful thing. >> reporter: spontaneous seminars to start students on their own road to discovery. a cross-country classroom launching a journey of a lifetime. halley jackson, sacramento.

>> that will do it for us on a thursday night. i'm lester holt. for all of us at nbc news, thank you for watching and good night. nbc bay area news starts now. right now at 6:00 are they lost in the snow? growing concern tonight about an east bay father and two children that vanished in the sierra. good evening, thanks for joining us. >> it is cold, windy, and snowy. despite the elements search teams are scouring the sierra tonight. they're looking for this east bay father and his two children. they went on a camping trip on sunday near truckee, but they never made it home. jodie hernandez is in alameda

this evening at a well-known barbershop that the family owns. >> reporter: nick is a co-owner here, he also co-owns the alley barbershop in oakland, he is well known here in the east bay. his friends tell us that he took two of his three small children just three and five years old camping with his mother and stepfather over the weekend. it's something that the family does quite often, only this time, they haven't come back. >> he takes them camping a lot. they're used to being in the truck with him on jeep trails and it's just one of the things they do. >> reporter: rick ra hoesnick rajos and two children have failed to come over. there's a rescue under way. friends say they should have been home two days ago. >> they're just confused. you know this is one of those things that you see on the news