versus global warming, his name is alec, from southern california and cnn founder, ted turner. it was just one of 50 around the world urging governments to take immediate action on climate change. the young leader of this movement sayayl ehe goa tof march is to get many young people involved to help the ruling generation take climate change seriously. good night. the bin laden tapes. what newly released videos and a huge seizure of intelligence reveal about osama bin laden. plus, the latest on what pakistan knew about his whereabouts. state of emergency. hundreds more are told to evacuate as the mississippi river rises, threatening to make severe flooding even worse. the survivor. a remarkable story about a woman stranded in the wilderness for seven weeks until some hunters found her. and the reunion. brothers who never knew each other until the chance encounter of a lifetime. captions paid for by nbc-universal television

from nbc world headquarters in new york, this is "nbc nightly news" with lester holt. >> for almost ten years osama bin laden taunted his viewers with video tirades against the west. tonight the tables are turned and there is growing reaction to those newly released bin laden videos that he apparently did not want the world to see. those videos of bin laden in hiding are now central to an american campaign to unravel his mystique and demoralize his followers. those videos, of course, are just part of a major intelligence find from bin laden's pakistan safehouse that the u.s. is rapidly trying to exploit. nbc's jim miklaszewski joins us from washington with the latest. >> good evening, lester. u.s. intelligence officials are calling this the biggest haul of secrets from a top terrorist leader ever. it includes bin laden home videos which they were very eager to release.

>> reporter: this is the video the white house wants the world to see. osama bin laden, once the world's most notorious terrorist, seen here with a tv remote as he dials up old videos of himself from a time when the mere mention of his name brought fear. but these are images of an old man in a stocking cap bundled up against the cold. and in spartan surroundings, nothing close to a mansion. unlike earlier videos where his beard is died black, here it's almost totally gray. in fact, u.s. officials say it's the same gray beard bin laden had when the navy s.e.a.l.s shot and killed him. >> at the end, here he died isolated, a prisoner as much as if he'd been in maximum security. >> reporter: other videos show bin laden stumbling through prepared remarks, looking off camera for some sort of direction. but if bin laden was so out of touch, how did he avoid detection for nearly five years? only 35 miles from pakistan's capital. and in the shadow of the

country's top military academy. president obama suspects bin laden had to have had a support network inside pakistan. >> we don't know whether there might have been some people inside of government, people outside of government, and that's something that we have to investigate and, more importantly, the pakistani government has to investigate. >> reporter: many in congress also have their doubts. >> it is extraordinarily hard to believe that he could have survived there for five years or more in a major population center without some kind of support system and knowledge. >> reporter: and not only survive. national security adviser tom donilon told nbc's "meet the press" that evidence gathered at the compound shows bin laden was still calling the shots for al qaeda. >> osama bin laden was involved operationally a strategic direction, in the direction of operations, including their propaganda efforts, obviously. >> reporter: intelligence also shows before his death bin laden was still intent on killing

americans. attacking u.s. targets such as trains, which would result in mass casualties. the first test of u.s./pakistani relations since bin laden's death could come this week. pakistani intelligence is interrogating bin laden's three wives and four other women taken into custody at that compound. the u.s. has asked the pakistanis for whatever information they get from those interrogations be provided to u.s. intelligence. there has been no word yet on just how forthcoming they'll be, lester. >> jim miklaszewski in washington, thanks. those behind the scenes bin laden clips are playing to a pretty tough audience in pakistan, bin laden's apparent home for the last several years. nbc's peter alexander has been sampling opinion in islamabad and has our report from there. >> reporter: the release of new video showing osama bin laden made headlines across pakistan. but did little to convince people here he had lived among them for years. >> we think this was a very big drama from the u.s. and other

governments. >> reporter: most remain deeply skeptical, even suspicious, of the u.s.'s version of events. we showed the videos to a former head of pakistani intelligence who dismissed the clips as meaningless. >> this doesn't prove anything. it doesn't prove he is still in charge. it doesn't even prove that this is the same room or the same house where he was living. >> reporter: is it possible that osama bin laden lived in abbottabad for more than 5 1/2 years without the help of anyone within the pakistani intelligence or military? >> i am absolutely certain that it is possible. and i am absolutely certain that the military or the isi did not provide him any advice. >> reporter: to piece together bin laden's movement since 9/11, pakistani interrogators are investigating three of his wives. the youngest reportedly told

authorities they lived here, just a half hour outside of islamabad as early as 2003. this is a rural farming village. a place where villagers say everyone knows one another. and they say it's impossible that a 6'4" foreigner, a man with a large family and a familiar face like osama bin laden, could ever have hidden here. no stranger could come here and dare to stay, this man explains. to many observers, the u.s. and pakistan are engaged in a pr war with the u.s. insisting up until his death bin laden actively controlled al qaeda from his compound. but pakistani officials claim bin laden was just an aging terrorist, a spiritual leader, whose ability to communicate with his followers was severely limited. peter alexander, nbc news, islamabad. >> for more on all this, we're joined by nbc news terrorism analyst, roger cressey. roger, we're told that the u.s. is already sharing some of the intel from bin laden's hideout with other countries. are officials essentially racing against the clock for fear some of this material is going to get

dated or stale quickly? >> i think that's right, lester. what we have here is we have actionable threat information. and that by sharing it with our allies, they may be able to take information they already have in their possession, piece together what we discovered in bin laden's compound and learn about potential plots. so it's putting the pieces of the puzzle together. there is a bit of a race against time involved here. >> the official u.s. narrative is that he was still somehow in charge of this operation, this al qaeda operation. and drawing up plans for attacks. but yet nothing major has happened, no follow-up attack to 9/11. was he discovering that his network was unraveling? >> well, lester, we've had tremendous success over the past ten years. we have pounded al qaeda relentlessly in pakistan and elsewhere. that's one of the main reasons why they've not been able to duplicate their 9/11 success inside the united states. but what this demonstrates with the information we found and bin laden's operational role is that the threat is still very real and we need to be equally relentless. in continuing to destroy their infrastructure. >> roger cressey, thank you very much for your insight.

appreciate it. another major story we're following tonight here in this country, the continuing rise of the mississippi river which is threatening parts of memphis, tennessee. nbc's jay gray is there tonight for us. jay, good evening. >> reporter: good evening, lester. i'm standing in an area for prospective that is normally an area for playground for kids at a montessori school. it is literally a part of the river now. as you look behind me you can see that row of houses. what you can't see is that they have a lower level that's been swallowed by the water there. coming back across you can see just the top of a storage shed there. that's all that's left. over to the school now where a sandbag wall built by volunteers, teachers, parents, is now being tested. the water continues to climb almost as quickly as the concern in memphis. >> for me, it's where is it going to happen? where is it going to stop? >> reporter: already 47 feet past major flood stage and

forecasters say on the way to a near record crest at 48 feet as early as tomorrow night. >> it's all astounding. it's just overwhelming to see it so high. >> reporter: hundreds have been drawn to the water's edge as it creeps closer to the city. some to take a picture. others to stop and stare. >> all the people that have lived here all their lives are seeing a completely different thing than they've never seen. >> reporter: they're watching but not waiting here. right now memphis is engaged in a full-on fight against the floodwaters. at times it's hand to hand combat. other battles waged with heavy equipment. but in neighborhoods like this one, the weapons don't really matter. mother nature is winning. >> i had to get my possessions all together. >> sir, we got to go. >> reporter: for residents on the north side of the city, this was one of the last chances to move to higher ground. >> i tried to leave yesterday evening and it was -- i couldn't

get out. >> reporter: emergency teams went door to door and loaded a handful of holdouts on to a bus that pushed through the rising water to safety at this staging center. >> i didn't think it was going to come that fast. they said it would come this weekend. last night there wasn't any water in the trailer park. now i look out this door and it was four feet deep. >> reporter: almost as big a worry as the water is what will be left behind. and right now about 400 people are in memphis area shelters. emergency managers say that number could surge to thousands before this is all over. lester? >> jay gray, a dramatic view of the flooding there tonight. thanks. this was a mother's day like no other for a canadian woman recovering tonight after being stranded in a remote part of nevada for almost two months. we get the story tonight from nbc's george lewis. >> reporter: back on march 19th, albert and rita chretien left their home in pentington, british columbia and headed for a las vegas trade show.

that same day a surveillance camera photographed them at a store in eastern oregon. the last pictures of the two of them together. 400 miles later in the nevada backwoods, their van got stuck in the mud. >> our understanding is that they took a few wrong turns. they wanted to take a scenic route. >> reporter: the van wound up in this wilderness area of nevada just south of the idaho border. rita stayed alive seven weeks subsisting on beef jerky and trail mix, eating snow and drinking from a nearby stream. after 49 days, her strength waning, rita spotted some people riding all terrain vehicles and flagged them down. >> she convinced them that she needed help and they went and got help for her. >> reporter: at this idaho falls hospital where she's recovering, she was able to spend mother's day with her son and daughter-in-law. >> we were praying for a miracle and, boy, did we get one. >> reporter: now they pray that rita's husband, albert, will somehow be found alive. three days into the ordeal he

took off carrying a gps device, looking for help. today the search for him was suspended because of bad weather. rita's doctors at the hospital say they're amazed at her remarkable recovery. >> i must say that it is unusual for us to see someone in this type of situation to actually not only survive, but to be doing so well at this time. we certainly are very experienced with various degrees of starvation in our line of work. but this most certainly is a once in a lifetime experience for all of us. >> reporter: her children say the prayers for albert continue as the search for him is set to resume in better weather. george lewis, nbc news, los angeles. when we come back here tonight, beyond bin laden. the continuing terror threat and where it comes from. richard engel on the worldwide terror trail. and the amazing chance meeting that brought together brothers for the very first time. t

american officials have said repeatedly in the last week that osama bin laden's death does not mean the end of al qaeda or the threat of terrorism. but with bin laden gone just where does the threat come from? we put that question to nbc's chief foreign correspondent, richard engel. >> reporter: like a hydra with many heads, cut one off, the beast doesn't die. osama bin laden ran what counterterrorism experts often call al qaeda central. its corporate headquarters.

bin laden's central command planned the big attacks like 9/11 and the 2004 train bombings in spain. but al qaeda also has many small, self-sufficient heroes. now that al qaeda central is in disarray, the franchises could take over. since 9/11 we've met members of the al qaeda bureaus and found them to be dedicated, self-funded and driven by an al qaeda ideology. not bin laden personally. >> there's every reason to believe that now they are operating largely under their own banner. >> reporter: today al qaeda satellites are active in yemen, somalia, pakistan, iraq, jordan, indonesia and even the ungoverned western sahara desert. the most dangerous to americans, experts say, is the one in yemen. the u.s. backed yemeni government is so weak it can't control its territory. al qaeda in yemen also has a track record of attacking the united states. the underwear bomber in 2009.

a computer printer bomb shipped to chicago a year later. al qaeda in yemen also has a charismatic recruiter, anwar al awlaki. a native of new mexico, al awlaki's sermons are widely distributed online. he could become the new voice of al qaeda, with an american accent. al awlaki is considered so important, the united states tried to kill him thursday with a drone attack, but missed. somalia is another powder keg. when we visited last year, it was clear that al qaeda inspired militants have more than a safe haven here. they control about half the country. they also have an american-born recruiter. an alabama native who has even tried to attract new members by posting a song on the internet. ♪ i'm going to act my vengeance ♪ >> reporter: what does al qaeda's transformation mean for american security? on the upside, analysts believe the small al qaeda franchises don't appear to have the capability to carry out another

attack on the scale of 9/11. the downside could be more frequent, smaller attacks. then, lester, there is the issue of competition. with so many small al qaeda groups vying for prestige, some analysts worry they could try and one-up each other by launching attacks. >> richard, where is zawahiri, who we were told all these years is the number two in al qaeda? >> reporter: zawahiri probably will become number one in al qaeda central. but that organization after bin laden's death, after the seizure of so much material, is severely weakened. and what we're more likely to see is the rising of these smaller groups from yemen, somalia, and their attempts to take over the organization. >> all right. richard engel in libya for us tonight, thank you. next up here tonight, medical news. a potentially life threatening problem for children much bigger than anyone thought.

important health news. a new study to be published in the journal pediatrics will show a big increase in the number of children who suffer from food allergies. some of them can be life threatening, including severe peanut allergies. nbc's kerry sanders has more. >> reporter: in the shadows of colorado's pike's peak, 6-year-old lily martin learns math with her first grade classmates. but lily is different from her friends. she carries a life saving syringe with her everywhere she goes. what is that? >> epi pen. >> epinephrine to protect lily from peanuts. she among an estimated 5.9 million children who have food allergies. what could happen if you had a peanut? >> i would swell up. >> reporter: her throat would swell up and possibly choke her to death, says her doctor. like 9-year-old nathan walters from spokane who died after a peanut exposure while on a field trip. or 14-year-old anna of arizona,

in a coma after eating cereal she didn't know had peanuts. a new study funded by the food allergy initiative in an upcoming issue of "pediatrics" found 1 in 12 children have food allergies. that's almost twice as many as initially thought. 40% of those with allergies have a life threatening condition. >> say aww. >> reporter: at lily's once a year allergy test, a pinprick with a microscopic droplet of peanut extract turns into a hive. >> yeah. she's still allergic to peanuts. >> reporter: in colorado springs to keep lily safe from peanuts, everyone, even visitors, washes their hands when entering the classroom. >> we are a peanut free environment. >> if i come in, i have to wash my hands. >> you do, absolutely. >> reporter: not every community is so accommodating. in edge water, florida, there's anger that so many students had to rinse their mouths and wash their hands repeatedly for just one child with an allergy. back at lily's school, kids still bring their favorite pbjs.

lily and her friends eat their lunch at the same time. but over in the allergy free zone. separate but equal. kerry sanders, nbc news, colorado springs. >> in bath, maine, this weekend, a special honor for a young american who made the ultimate sacrifice. a navy destroyer was christened the "uss michael murphy" after a navy s.e.a.l. killed six years ago during a firefight in afghanistan. his mother cracked a bottle of champagne against the hull of what would have been her son's 35th birthday. after his death michael murphy was awarded the medal of honor. up next here tonight, an astonishing twist of fate that brought long lost brothers face to face.

finally, as we celebrate mother's day, a story of family. a chance encounter that brought together perfect strangers. turns out, they're brothers. nbc's kevin tibbles reports. >> reporter: of the millions of snapshots taken on waikiki beach, this one is so very special. rick hill from outside boston was vacationing in the sun when his family paused for a photo.

that's when a stranger approached. >> and basically he came up and he says, why don't you jump in the picture and do a whole family shot. >> reporter: that stranger, joe parker, also from outside boston, grew up in foster care. and was now living in hawaii. >> i saw these people enjoying waikiki and on vacation. and just wanted to be a little hospitable. >> reporter: rick hadn't even planned to be on the beach that day. yet here he was reminiscing. his hometown was just one away from joe's. and then the name. >> then he just out of the blue came out with -- he asked me if i knew a guy named dick halligan. at that point i said, yeah, that's my father. >> i lifted up my sunglasses. i looked him dead in the eye and i said, you know, that's my father, too. >> reporter: dick halligan died nine years ago. while each knew of a half brother, that was all they knew. is fate something you believe in? >> fate. miracle. whatever words you want to use to describe it.

yeah. absolutely, i believe in something beyond me. >> reporter: the pair continued catching up this morning on "today." >> every day we've talked at least once or twice. took us half our life to meet, but it's been exciting, to say the least. >> reporter: and what do you know? after 38 years of not knowing one another, they're already starting to sound like brothers. >> you know, he's got quite a bit of issues. he's got a face for radio. but, no. there are a lot of similarities. there's a lot of mannerisms that i see from my father that i see in him. and we do have a lot of stuff in common. >> except for the hair. i mean, if i had hair, i certainly wouldn't do what he does to his. >> reporter: a chance meeting on a beach. a lifetime ahead together as brothers. kevin tibbles, nbc news, new york. and that's "nbc nightly news" for this sunday. you can follow us on twitter and facebook. we'd like to hear from you. brian williams will be here tomorrow. i'm lester holt. reporting from new york for all