on our broadcast tonight, twisters. the terrifying scene in texas as it unfolded on live television. tornados sweep across dallas/ft. worth, tossing trucks into the air and raising the question, what is going on with our weather? moment of crisis. chilling new details now about what happened inside that deadly school shooting. decision day in three battlegrounds. can romney put santorum away? plus, the president decides to name names in going after the gop. and tipping the scales. new research on obesity, and a way of measuring it which may change the rules and surprise a lot of women. "nightly news" begins now.

captions paid for by nbc-universal television good evening. we got a chance to witness a rare sight today, and an awesome one at that. a tornado rolling in over a major metropolitan area. as we watched it happen live, as it was captured by television news helicopters, here's what it looked like this afternoon in dallas/ft. worth. those large flying projectiles are 18-wheeler truck trailers from a trucking company yard south of dallas. it went on from there to hit numerous neighborhoods in the dallas metro area. then the second wave of storms came along behind it. and at the sprawling american airlines hub at dfw airport, that was shut down, passengers sheltered inside, kept away from windows, while dozens of jet aircraft exposed on the tarmac had to be inspected for hail damage. well, it's where we begin tonight. nbc's gabe gutierrez is with us

from lancaster, texas, where the worst is over from above, but a mess remains there on the ground in lancaster. gabe, good evening. >> reporter: good evening, brian. dallas area residents were alerted earlier this afternoon that tornados might be possible. but no one expected this, two monster storms leaving behind all this damage. just look at those up ended cars behind me. unbelievably, no injuries have been reported. >> dang, i can't believe this. >> reporter: the massive funnel clouds sent debris. >> guys, it's throwing 18-wheelers. >> reporter: trailers and sparks flying. >> just crossed over i-20 northbound. there's lots of 18-wheelers. this is something i've never seen before. >> reporter: dallas/ft. worth airport shut down. with airlines serving dfw reporting that more than 110 aircrafts sustained varying degrees of hail damage from the storm. news choppers were in the air as

the funnels formed. on the ground tonight, the devastation that only a tornado can bring. >> it picked us up, and slammed us down. >> i heard a thump, turned around and here was this truck. >> i got into a bathroom that's in the inner quarter of the half. and about three minutes later, anouene d t tht d the tornado came through our house. >> reporr: the two tornados ep missed the city of dallas, but cut a destructive path across the met pot an area. >> it looked like it was coming toward me. >> reporter: wes stevens was on his way to a meeting when he saw the first sign of the storm coming. he pulled over and shot this video. >> i wasn't going to be able to back up. i couldn't outrun it. fortunately it went straight across the road and i took off. after i was driving off, i looked over and could see the transformers exploding, and the green lights shooting up in the air. it looked like it tore some shingles off some roofs. i didn't see any houses destroyed or anything. but i saw quite a few -- it did

twist up an exit sign on the side of the road. >> reporter: local businesses, from car rental companies, to nursing homes and schools across the area were shut down due to the storms. at the gaylord texan hotel, staff and guests were evacuated into tunnels below ground. and schneider national trucking, the company that owned those orange trailers, they're trying to come to grips with what they say is a devastating loss. dfw airport has reopened, but thousands of passengers tonight are stranded, that's because hundreds of flights were cancelled and many hotels and businesses are still without power. it appears it's going to be a very long night here. >> gabe gutierrez starting our coverage from lancaster, texas tonight. gabe, thanks. dr. greg forbes is the severe weather specialist at the weather channel. he's been on the air all day covering these storms from their atlanta headquarters. dr. forbes, we've been watching your coverage all afternoon and evening. and when people see this, they ask the same question, what's going on with our weather? how common is not only an early

april tornado in texas, but an outbreak of them in the major metropolitan area? >> certainly in the metro area, that's really the odd thing today. it's been so localized. but on this date, april 3rd, 1974, we had the original super outbreak, 148 tornados in 24 hours. so early april can have these kind of tornados. i do have a graphic that shows why it was so much just texas today. a big spinning upper air low and its cold pocket, the leading edge pushing this cold front eastbound. it's mainly this red and blue stationery front, drifting winds, those are often the focal point, that ran right through dallas. that's why all the storms that were basically producing tornados were right in the dallas/ft. worth metroplex and have pushed further off toward the north and east. but they're focused right along the narrow area, right along the frontal zone. brian? >> dr. forbes, in watching your coverage today, you seemed to say there was good news.

all the sirens sounded. notification worked. they weren't as severe as the tuscaloosa sized storms we've seen. >> yeah. >> the bad news was, you said these were moving slowly, about 25 miles an hour over land. and that can make a storm dwell over an area? >> yeah, that can make the winds linger longer over locations. it's just amazing how the levitation of those tractor-trailers twirling around in the air -- i had never seen video like that. very, very lucky, if we get through this without serious injuries or fatalities, considering the kind of upward motion, and must have been pretty strong horizontal motion also in these tornados today. >> dr. forbes is the man to watch when there is severe weather. dr. forbes, thank you very much, as always, for being with us tonight. now to the shooting we told you about here last night, at a small college in oakland, california. we learned more today about the alleged gunman and what might have motivated him to open fire. police say the seven people killed and three wounded may simply have been in the wrong

place at the wrong time. our report from nbc's kristen dahlgren. >> reporter: instead of students today, crime scene investigators filled oikos university, searching for clues in what police are calling a calculated, cold-blooded execution by an expelled student. >> just walk in the room and tell them, everybody against the wall. i'll take care of you guys today. and then he pulled the gun and started shooting. >> reporter: police say it was a massacre that 43-year-old suspect one goh may have been planning for months. >> we do know that he was upset at administrators at the school. we do know he was upset with several students here because of the way he was treated when he was enrolled here two months ago. >> reporter: the former student was targeting a female administrator at the school. he asked for her, but when she wasn't there -- >> he went through the entire building, systematically, randomly shooting victims.

>> units be advised we have live fire. >> reporter: six women and one man were killed. one was a school secretary, the rest students. their ages range from 21 to 40. most studying nursing at the small christian college, known for its diverse student body. >> the victims are from various countries, including korea, nigeria, nepal and the philippines. >> reporter: in goh's native korea, the killing was front page news. the south korean government expressing regret. and as the community here tries to cope, police continue to search for the murder weapon, believed to be a semiautomatic handgun, according to police, purchased legally six weeks ago, by the man they say is cooperating, but showing little remorse. goh is scheduled to have his first court appearance here in oakland tomorrow. in the meantime, a memorial will be held for the victims tonight, brian? >> kristen dahlgren in oakland, california. kristen, thanks. now to the race for

president playing out tonight on multiple fronts in three gop primaries. and what is being called a full frontal assault today by the president on the republicans. our political director and chief white house correspondent chuck todd with us from our d.c. newsroom tonight. chuck, good evening. >> reporter: good evening, brian. first, we have results in two of the three primaries being held today. in maryland, no surprise, mitt romney is projected as the winner. according to our estimates, he's going to win by a very large margin over rick santorum. in the district of columbia, santorum was not on the ballot. nbc projecting mitt romney will win there as well. romney hopes to wrap up the nomination, perhaps as early as tonight, so he can focus on president obama, who stepped in the fray himself today, in a very big day. as mitt romney spent this primary day in wisconsin

campaigning with congressman paul ryan, the architect of the gop's congressional budget proposal, president obama took to a washington d.c. hotel ballroom filled with america's newspaper editors to eviscerate the ryan plan. >> an attempt to impose a radical vision on our country. thinly veiled social darwinism. antithetical to our entire history. >> reporter: and the president used unusually sharp rhetoric and sarcasm, not just to attack the budget plan, but to attack romney personally for supporting it. >> and he even called it marvelous, which is a word you don't often hear when it comes to describing a budget. it's a word you don't often hear generally. >> reporter: and he even tried to capitalize on the divisive republican primary campaign. >> that renowned liberal newt gingrich, first called the original version of the budget radical, and said it would contribute to right wing social engineering. >> reporter: the entire speech was a verbal blueprint of how the president this election year will attempt to paint the entire republican party as out of the

mainstream. >> the positions i'm taking now, if we had been having this discussion 20 years ago, or even 15 years ago, would have been considered squarely centrist positions. what's changed is the center of the republican party. >> reporter: ryan compared the speech to what he called the president's reckless budget, adding, it was as revealing as it was disappointing. and romney said the president was unwilling to take responsibility for his own mistakes. >> and so today, instead of standing up and saying, as the president, his policies have not worked, he will look for someone else to blame. >> reporter: late today, newt gingrich said the president took his criticisms of ryan out context. gingrich now says any issues he had with ryan's initial budget have been resolved.

and brian, big picture for a second, let's remember what this fight is about between the two parties. whether a big chunk of deficit reduction money will come from tax increases on the wealthiest or existing government programs. brian? >> chuck todd our political director on all things politics tonight. we have a quick update on former vice president dick cheney. he's back home tonight, released earlier today from a virginia hospital, just ten days after receiving a heart transplant from an anonymous donor. cheney, who is seen here with his wife lynn is 71 years old. this photo showing the fit mr. cheney was put out on twitter today by daughter liz cheney. still ahead as "nightly news" continues on a tuesday night. does this woman look obese? tonight, the surprising new face of an epidemic. tonight, what millions of american women may not know about their own weight. and later, state of the art. masterpieces and places a lot of people can only dream of going to see for themselves, until now.

there is news tonight on this nation's growing weight problem, a problem that is actually getting worse than we first thought, because of how we measure it, especially when it comes to women. our report tonight from our chief medical editor, dr. nancy snyderman. >> reporter: it's no surprise that americans are getting fatter, but a new study finds the obesity epidemic could be a lot worse than anyone thought. the new face of obesity could actually look more like this. this is barbara hemerly-golask.

she's now at a healthy weight but a year ago, doctors determined she was obese. even though her body mass index or bmi, indicated she was normal. >> when i saw the results it was utterly shocking. >> reporter: bmi estimates a person's body fat based on height and weight alone. dr. eric braverman, who led the study, says the widely used method is overly simplistic and significantly underestimates the prevalence of obesity. >> bmi doesn't tell you how much fat you have. that is the predictor of heart disease, cancer, stroke, gallbladder, fertility problems, depression, anxiety, sleep disorder, et cetera. >> reporter: the study looked at 1,393 adults and found that 48% of women were misclassified as not obese based on bmi. for women, the bmi doesn't take into account the loss of muscle mass that comes with age. dr. braverman says a commonly used test to check for bone density, called a dexa scan, is more accurate because it

measures bone, muscle and fat. it also costs several hundred dollars. another approach is a simple blood test for leptin. a hormone associated with obesity. >> that is costing the country a fortune by not measuring it. a dollar blood test and doing our bone density scans at the same time, is going to pay off enormously. >> reporter: barbara now says she's a new person, and has the proof inside and out. the fact that the bmi was introduced as a measure of obesity almost 200 years ago just adds fuel to the fire that it's really outdated. and truth be told, the same way americans got used to measuring ldl and hdl as part of a cholesterol test, well, perhaps it's time to get used to dexa scans and leptin blood tests and really tackle this whole issue of obesity in a more sophisticated way, brian. and head on. >> a bit of a rule change. >> this is a shocking one.

americans are back in the car market, apparently in a big way. and the high cost gas may have a lot to do with it. most carmakers had their best month of march since '07. chrysler sales up 34%. gm up 12%. ford up 5%. the rising cost of gas along with low interest rates is a big part of what's driving people into showrooms to replace the aging cars they've been hanging on to during this downed economy. up next here tonight, that ghost ship we told about you from the tsunami in japan. tonight there's an update. and an amazing story of a grandmother who had to take control an aircraft in mid flight. the problem was, she didn't know how to fly.

it was a beautiful early spring day in northern wisconsin yesterday. and as a small plane prepared to

land at a local airport, no one looking on could have imagined the drama that was playing out inside in the sky. nbc's kevin tibbles has the story. >> reporter: the nose gear collapsed on landing, but that landing was nothing short of miraculous. john and helen collins were returning to sturgeon bay, wisconsin, from florida, when 81-year-old john lost consciousness and died while at the controls. >> she does not know anything about flying whatsoever. >> reporter: helen collins had been flying with her husband for decades. while she had some flight training years ago, she wasn't at all familiar with the controls of the cessna. she ended up using her cell phone from the air to call 911. >> hopefully she doesn't crash. >> reporter: a pilot then took off from sturgeon bay flying alongside the cessna to talk her down. >> i was able to monitor what she was doing in her aircraft by what was happening in my aircraft. >> reporter: after circling the airport for more than an hour, one of the engines ran out of

fuel. but helen collins brought the plane in for a hard landing. it bounced some 30 feet before coming down again. >> reporter: it was only then when the pilot realized he lost one friend and saved another. >> happy and sad at the same time. we move on. >> reporter: 80-year-old helen is being treated for injuries, while everyone involved with the flight marvels at her courage. kevin tibbles, nbc news, chicago. >> amazing story. we also have an update tonight on that so-called ghost ship that's been adrift, making its way across the pacific since it became unmoored by the tsunami in japan. the coast guard was able to able to capture it on video while they dropped a tracking buoy alongside. it's a shrimping vessel. it appears to be between 150 feet and 200 feet long. and it also appears generally

headed to sitka, alaska, about 175 miles away. when we come back tonight, an extraordinary new view of some of the great treasures of the art world.

finally tonight, at a time

when schools are cutting back on funding for arts education, there's some good news. google is stepping into the breach with a project that is part google earth and part museum of art. but it's meant to bring art to us. the story from nbc's kate snow. >> what do you notice about van gogh's face? >> reporter: holly's third graders in seabrook, texas, are on a field trip visiting a museum 5,000 miles away in amsterdam. >> you kind of see a lot of different textures. >> reporter: google art project founder never had access to the world's great art. there are a lot of american school children who will never come to the museum of modern art in new york. >> well, soon they'll be able to go to india, brazil, russia. >> reporter: the people who brought us google earth, google oceans, street view have been mapping the world's museums after dark. 150 collections in 40 countries are online tonight. from the acropolis in greece to the street graffiti in brazil,

bocelli and norman rockwell. let's say you missed jackie kennedy's famous white house tour. now you can cruise by the famous picture of george washington with just a click. and remember the scene from "ferris buehler's day off"? google's art project let's you zoom in and get a better view than cameron ever did. >> look at this part. this is one of my favorite parts of the painting. when we do it over here, zoom in here, and just really quickly move to that exact same area, you start seeing the cracks and the brush -- >> despite how big the google art project is now, there are limits. this whole gallery is on the virtual tour, but right around the corner, a room full of picasso's that you won't see online. at moma, they hope putting part of the collection online spurs more people to visit. >> nothing's better than seeing an artwork in person. there's just something that happens to you when you're in the presence of a real work of art. it's visceral, emotional. >> reporter: even state of the

art art is no substitute for the real thing. kate snow, nbc news, new york. that's our broadcast on a tuesday night. thank you for being with us, as always. i'm brian williams. and we hope to see you right back here tomorrow evening. good night. -- captions by vitac -- www.vitac.com good evening. i'm jessica aguirre. >> and i'm raj mathai. it's one of the deadliest mass killings in california history, and tonight we're getting our first look at the accused gunman. police say 43-year-old one goh was seeking revenge and now police are searching for the murder weapon. we have live team coverage tonight. marianne favro has the emotion al reaction from the victims' family and