maybe a chance of thunder. there you go. first weekend of spring. >> lovely. nbc "nightly news" is next. more local news at 6:00. we'll have a story about a anine officer under nt.sauzcr e enseth ig n.ht on this saturday nigh, breaking news. nbc news has learned that former vice president dick cheney is in intensive care after a heart transplant. tonight, the latest on his condition. captions paid for by nbc-universal television we begin with breaking news. we learn that dick cheney is recovering in the intensive care unit of a falls church,

virginia, hospital after undergoing a heart transplant today. the 71-year-old cheney has had a history of heart problems. two years ago, he suffered his fifth heart attack since age 37. the former vice president had been on the cardiac transplant list for more than 20 months before today's surgery. jamie, good evening. >> reporter: good evening, lester. this announcement came as a surprise because up until now, the former vice president maintained he had not made a decision about having a heart transplant. however, now we know he had been on the transplant list for 20 months since he went into late stage heart failure in the summer of 2010. at that time, cheney had a left ventricular device. it runs on a battery pack that the former vice president carried with him for the past 20 months. most patients with this type of device do not stay on it for more than two years. so he really needed this heart

transplant. nbc news has also learned that he actually reached the top of the transplant waiting list this past december. so mr. cheney has been waiting for a match since then. coincidentally, lester, i actually saw the former vice president just a few weeks ago and while he looked fine, it was clear he was having breathing problems. in a statement released earlier this evening, the cheney family said although they do not know the identity of the donor they will, quote, forever be grateful for this life-saving gift. and really, lester, even though mr. cheney has had this long history of heart disease, this transplant is another example of his being the beneficiary of the extraordinary strides that have been made in medical science. lester? >> jamie gangel. robert, as has been noted, he's

been wearing that assist device for a coup of years. is it typical to wait that long for a heart? >> a lot of people don't b even survive being on the waiting list, lester. only about 1,800 hearts become available in the united states every year for transplantation. and a lot of people die waiting, because there's just a shortage of donors. but now that he's got the heart, mr. cheney's prospects are pretty good. overall, 88% of men who get a heart transplant survive for a year even 73% survive for five years. so he as, as jamie pointed out, been the beneficiary of many, many advances in heart treatment and here he is if yet getting another one. he could live many years more. >> i want to go back to being on the list. what does that say in terms of your ability to go beyond a certain border or boundary while you're on that list? >> for the average person, it means they have to carry a beeper and come into a hospital in a matter of hour once it's learned there's a matching heart donor.

that means that somebody is brain dead and they're going to extract their heart and transport it to where the recipient is. he knew he would have to go to the hospital within hours and he's been aware of that possibility. obviously somebody who has secret service protection has a lot more aids at his side all the time. it wouldn't be the same for a typical american, but still, the process is very much the same. and whether you get one or not has nothing to do supposedly with how important you are. it has to do with when a transplant is available. >> robert bazell, thank you for squo joining us. tonight, nearly a month after the death of trayvon martin, george zimmerman has not been charged with something, but now with new criminal investigations under way amid a nationwide uproar, the 28-year-old neighborhood watch volunteer is tonight being offered up in a new light. nbc's ron allen continues to

work the story tonight from sanford, florida, and joins us now. sflon. >> good evening, lester. george zimmerman's attorney is trying to cast him as the victim. forced to fire in self-defense when attacked by trayvon martin. he's certainly not going to win that argument in the court of public opinion, but it also seems clear now that zimmerman is going to do everything possible to keep this case from ever getting to a court of law. >> we are! >> trayvon! >> while the daily drum beat of protests rages on and the demand for justice for trayvon martin continues to spread like wildfire, george zimmerman supporters step up their own public pushback. even a new more recent fot lphos appeared, obtained from this mortgage firm where he is or was recently working as a loan review analyst. and an attorney is now telling zimmerman's side of the story. >> i have advised h him to stay out of the public as much as he can. >> reporter: his attorney says he fears death threats and

vigilantes. a black activist group has renewed its $10,000 bounty for anyone who finds zimmerman. that follows the arrest of a man who threatened to kill the local chief of police. >> the ultimate issue was that there was some kind of scuffle took place and there was a gun that was discharged and now a young man is dead. >> reporter: the lawyer added that that he had a broken nose and needed stitches. >> that's the operative word. watch. it does not say approach, point, arrest, shoot, kill. >> reporter: tina chestnut is a watch block captain in an orlando neighborhood notorious for high crime. she says the work she's been trained for is nothing like what zimmerman apparently was doing the night he encountered trayvon martin. >> we are not to pursue, we are not to call out or ask anyone not to do anything.

that's why we utilize 911. >> reporter: some 25,000 neighborhood watch groups operate in the u.s., a program in existence since the 1970s. >> as far as we're concerned, there should have been nor intervention, nor should there be any weapon involved whatsoever at anytime. >> reporter: today, we also learned from the national association of black journalists that the martin family plans to file a civil lawsuit, probably targeting the homeowners association that runs the crime watch program that zimmerman was on patrol for that evening. lester? >> ron alsoer len, thanks. at least eight people are dead. most of them children after an early morning fire raged through a home in west virginia. as the city of charleston deals with what's being described as the deadliest fire there in decades, it's another reminder of the importance of the early detection of danger in your home. we get the latest now from gabe gutierrez. >> reporter: flames tore through this charleston, west virginia,

home, killing eight people including six children ranging in age from 18 months to eight years oled. another child is in critical condition. >> by the time i heard yelling, i looked up, and i got out there and the house was in flames. >> this is the worst house fire in the city of the history of charleston and maybe west virginia. >> reporter: police say two adult sisters live in this rental home. their families gathered a slumber party on friday night to celebrate a birthday. alicia carter camp would have turned 26 today. >> this house was fully engulfed when units arrived and people were obviously in danger inside. >> reporter: the mayor says there were two smoke detectors in the home but neither was installed properly and it's not clear when the building was last inspected. >> had we seen the fact that they did not have the proper number of these smoke detectors, we might have saved a lot of lives. >> reporter: today's incident is an eerie reminder of that christmas day fire in connecticut where three children

and their grandparents died. there were no working smoke detectors in that home. in fact, 62% of home fire deaths are in buildings without working smoke detectors. >> then a's what the smoke detector is for, to wake you up, allow you time to get out. >> back in west virginia, investigators are trying to figure out what started this fire. and how a birthday celebration turned into a tragedy. gabe gutierrez, nbc news, new york. tonight we're learning chilly new details the night an american soldier was accused of leaving his base in afghanistan and slaughtering 17 afghan civilians. john i can't think john yang is at the post where robert bales is being held. good evening. >> reporter: good evening, lester. government prosecutors are alleging that robert bales carried out his rampage in two waves. he carried out a first attack,

they say and then returned to base and then snuck out again to continue his shooting spree. this is i cording to his defense attorney john henry brown who late today told nbc news this has been the government allegation from the very beginning. brown, of course, said that bales told him that he has a very spotty memory of that night. he can only remember some things before the incident and after the incident and has no recollection of the incident itself. lester? >> john yang, thanks. and a program note, monday on "today" staff sergeant robert bales' wife carolyn will speak out for the first time since charges have been brought against her husband. in an exclusive interview with matt lauer. overseas tonight, president obama is in south korea for a summit of dozens of world leaders, gathered to discuss the threat of loose nuclear materials around the world. our white house correspondent kristen welker has more from

seo seoul. >> reporter: good evening, lester. president obama heads to the demilitarized zone that separates north and the south today. it comes at a time of heightened tension over north korea's nuclear program. as south korean activists protest north korean military posturing, mr. obama is here for an international security summit to discuss ongoing efforts to keep nuclear materials out of the hands of terrorists. north korea's planned launch of a long range rocket in april that can put a satellite into orbit is overshadowing the meeting and threatens to derail an agreement by the u.s. to provide food aid if the north halts nuclear weapons tests. republicans have accused the president of being soft on korea and iran, which has rebuffed efforts to inspect its nuclear facility pss. with that criticism dogging imhim, the president is urging north koreans to get in line. the president also expressed

concern about the planned rocket launch to urge everyone involved to exercise restraint. back do you. >> too presidential politics now, another republican contest. today's louisiana primary comes after a wild week on the trail, filled with delegate math and and etch-a-sketch. ron motta is on the trail with us tonight. good evening. >> reporter: good evening. mitt romney is taking the weekend off the campaign trail louisiana is heavily evangelical. today, 52% of the voters down there today said that they are evangelic evangelical. that's a big base of support for rick santorum. he has won ten states on that support. but here in the industrial heartland, he hasn't had the same support. he's waiting for his first win here.

he chris crosses the badger state, looking to close the delegate deficit with mitt romney today. he joked that he would be okay if mitt romney dpe sided to quit the race, lester. >> thank you. white house senior adviser plouffe will be among david gregory's guests on "meet the press." still to come, raising questions about widespread cheating in our schools. and later, the dog that's not only a little girl's constant companion, he's also her lifesaver.

the possibility of widespread cheating on achievement tests that are used to measure how well our kids are learning and overall success rates in school districts across the country. a report out tonight builds on the paper's earlier investigation of of that city's schools. our story tonight from nbc chief education sport rehema ellis. kreert the resistant journal constitution published a seize of reports claiming test strides were foo good to be true and as extraordinary as a snowstorm in july. a statewide investigation by georgia's governor discovered systemic cheating.

principals and teachers from dozens of schools were implicated. the atlanta scandal prompted the newspaper to look further, analyzing more than 1.5 million standardized tests from 69,000 schools nationwide. the ajc found nearly 200 districts had suspicious scores that resemble those that entangled atlanta. >> in some cities, the scores changed so much that there's virtually no chance of it happening. you would have a better chance of winning the lottery. >> reporter: the paper says nine districts show inconsistencies so extreme the odds that they occurred without an intervention are more than 1 in a billion. according to the report at patrick lewis downtown academy in st. louis, 42% of fourth graders passed the state math test in 2010, just before state investigators began looking into possible cheating. the following year, only 4% of fifth graders passed.

in a statement to the ajc, district officials acknowledged the strangeness of score changes, but disagree that cheating was to blame. at ft. worthington elementary in baltimore, the paper also found as many as 20 mistakes were corrected on some exams, often in a lighter shade of pencil. the district issued a statement saying it has been zealous in our attack on cheating, and places external independent monitors in every school during state testing. reaction from other school districts varied but includes charges the ajc's report had errors in met dolg and test gains were due to increased reading and mathematics instructional time. when asked about the report, secretary of education arnie duncan said the findings are concerning. it's unclear what's behind the inconsistencies cited by the ajc. >> this encourages further exploration of these unusual patterns. but it doesn't necessarily mean

there's widespread cheating. >> reporter: the atlanta journal constitution points out, and we should to too that most teachers don't cheat. still, some experts charge that high stakes testing that links funding and jobs to student performance can lead to abuse. lester? >> thanks. up next, she looked like a queen. a surprise guest at a wedding today.

back now with the most famous pair of wedding crashers since vince vaughn and owen wilson. kw queen elizabeth and her husband phillip decided to pop in on some newlyweds. >> another city, another adoring crowd. but when you've been queen for 60 year, it's hard to pull a surprise. unless, of course, you drop by a couple's wedding, know their names, know where they're going on honeymoon and leave them stunned. >> i think it just hit us. oh, my god, it was like proper shock. it was only a few minutes, but to be so close up to somebody that you see so often on the tele. you know, it's diczar. >> john and francis canning were told a few weeks ago the queen would be at city hall as part of her jubilee tour of manchester. so they wrote to buckingham

palace to see if she would like to share their day and received a polite decline. it was so shocking a fellow guesting noed something over. after wishing the newlyweds well, she and prince phillip left. >> i'll never forget it. it's special getting married but -- >> i never would have forgot it anyway, but everything was such a bonus. >> reporter: no word yet on if the queen gave the couple a wedding president. perhaps gifts don't get better than this. more than a year now after the tsunami in japan, a boat that was swept away was spotted off the coast of canada. about 5 million tons of debris were swept into the ocean when the earthquake and tsunami struck in march last year. . when we come back tonight, a little girl and her best friend,

always beside her when she needs her the most.

finally tonight, the story of a young girl and her best friend in the world. she follows her wherever she goes. in fact, he's a real lifesaver. >> reporter: by all accounts, mr. gibbs looks like any other golden doodle much ppuppy, lovie scrunches and some naps. but mr. gibbs is here to work.

>> let's make sure we get it turned on. his boss? 3-year-old alita knoblauch. >> what do we got to do with mr. gibbs? >> down. >> reporter: this special little girl suffered from hyperplasia. it's an extremely rare lung disease requiring her to breathe with the aid of an oxygen tank. only 500 kmichildren in the uni states have ever been diagnosed with it. >> debbie was able to look up what all the tests they were doing. the first one, you know, she would have made it for 24 months. once the diagnosis was made, doctors told the knoblauchs they needed to leave utah and live in a lower elevation and that alita would need an oxygen tank at all

times. >> she started catching up quickly. >> reporter: but that led new problems for a toddler hooked up to a ten-point oxygen tank. the knoblauchs found dog trainer ashley kinsley and proposed the idea to have a service dog carry the oxygen tanks. >> for a service animal to do that with a 3-year-old, that's kind of the difficult park. >> reporter: but so far, mr. gibbs has passed the test and alita has a newfound freedom. >> what's your fif rate thing to do outside? >> swing. >> do you have mr. gibbs by you when you're swinging? >> he gets hit in the head. >> reporter: but lucky for mr. gibbs he's resilient and has a whole lot of patience. >> what do you say to mr. gibbs? >> down. >> reporter: do you have other things you say to him? >> uh-huh. >> reporter: like what?

>> at ease. >> reporter: now the knoblauchs can be at ease knowing their daughter is in good hands thanks to her new friend with four paws. >> reporter: what's your best friend? >> gibbs. that's nbc nightly news for this saturday. i'm lester holt reporting from new york on "today" and right back here tomorrow evening. good night. good evening, we begin tonight in the south bay where the search for 15-year-old sierra lamar is intensifying tonight.