Emergency workers pulled more than 100 survivors from the rubble of homes, schools and a hospital in an Oklahoma town hit by a powerful tornado, and officials on Tuesday sharply lowered the number of deaths caused by the storm.
The 2-mile (3-km) wide tornado tore through Moore outside Oklahoma City on Monday afternoon, trapping victims beneath the rubble.
Seven children died at Plaza Towers Elementary School, which took a direct hit, but many more survived unhurt.
"They literally were lifting walls up and kids were coming out," Oklahoma State Police Sergeant Jeremy Lewis said. "They pulled kids out from under cinder blocks without a scratch on them."
The Oklahoma state medical examiner's office said 24 bodies had been recovered from the wreckage, down from the 51 they had reported earlier. The earlier number likely reflected some double-counted deaths, said Amy Elliott, chief administrative officer for the medical examiner.
"There was a lot of chaos," she said.
Thunderstorms and lightning slowed the rescue effort on Tuesday, but 101 people had been pulled from the debris alive, Oklahoma Highway Patrol spokeswoman Betsy Randolph said.
Firefighters from more than a dozen fire departments and rescuers from other states worked all night under bright spotlights trying to find survivors.
President Barack Obama declared a major disaster area in Oklahoma, ordering federal aid to supplement state and local efforts in Moore after the deadliest U.S. tornado since 161 people were killed in Joplin, Missouri, two years ago.
"The people of Moore should know that their country will remain on the ground, there for them, beside them, as long as it takes," Obama said at the White House.
Glenn Lewis, the mayor of Moore, said the whole town looked like a debris field and there was a danger of electrocution and fire from downed power lines and broken natural gas lines.
"It looks like we have lost our hospital. I drove by there a while ago and it's pretty much destroyed," Lewis told NBC.
The National Weather Service assigned the twister a preliminary ranking of EF4 on the Enhanced Fujita Scale, meaning the second most powerful category of tornado with winds up to 200 mph.
The National Weather Service Storm Prediction Center warned the town 16 minutes before the tornado touched down at 3:01 p.m. (2001 GMT), which is more than the average eight to 10 minutes of warning, said Keli Pirtle, a spokeswoman for the center in Norman, Oklahoma.
U.S. Representative Tom Cole, who lives in Moore, said the Plaza Towers school was the most secure and structurally strong building in the area.
"And so people did the right thing, but if you're in front of an F4 or an F5 there is no good thing to do if you're above ground. It's just tragic," he said on MSNBC TV.
At least 60 of the 240 people injured were children, hospital officials said.
Witnesses said Monday's tornado appeared more fierce than the giant twister that was among the dozens that tore up the area on May 3, 1999, killing more than 40 people and destroying thousands of homes. That tornado ranked as an EF5 tornado with wind speeds of more than 200 mph.
The 1999 tornado ranks as the third-costliest tornado in U.S. history, having caused more than $1 billion in damage at the time, or more than $1.3 billion in today's dollars. Only the devastating Joplin and Tuscaloosa tornadoes in 2011 were more costly.
Monday's tornado in Moore ranks among the most severe in the United States http://link.reuters.com/gec38t
Jeff Alger, 34, who works in the Kansas oil fields on a fracking crew, said his wife Sophia took their children out of school when she heard a tornado was coming and then fled Moore and watched it flatten the town from a few miles away.
"They didn't even have time to grab their shoes," said Alger, who has five children aged 4 to 11. The storm tore part of the roof off of his home. He was with his wife at Norman Regional Hospital to have glass and other debris removed from his wife's bare feet.
Moore was devastated with debris everywhere, street signs gone, lights out, houses destroyed and vehicles tossed about as if they were toys.
The dangerous storm system threatened several southern Plains states with more twisters.
SAVED BY CELLPHONE
Speaking outside Norman Regional Hospital Ninia Lay, 48, said she huddled in a closet through two storm alerts and the tornado hit on the third.
"I was hiding in the closet and I heard something like a train coming," she said under skies still flashing with lightning. The house was flattened and Lay was buried in the rubble for two hours until her husband Kevin, 50, and rescuers dug her out.
"I thank God for my cell phone, I called me husband for help."
Her 7-year-old daughter Catherine, a first-grader at Plaza Towers Elementary School, took shelter with classmates and teachers in a bathroom when the tornado hit and destroyed the school. She escaped with scrapes and cuts.
Briarwood Elementary School, which also stood in the storm's path, was all but destroyed. On the first floor, sections of walls had been peeled away, giving clear views into the building; while in other areas, cars hurled by the storm winds were lodged in the walls.
At Southmoore High School in Moore, about 15 students were in a field house when the tornado hit. Coaches sent them to an interior locker room and made them put on football helmets, and all survived, the Oklahoman newspaper said.
(Additional reporting by Alice Mannette, Lindsay Morris, Nick Carey, Brendan O'Brien and Greg McCune; Writing by Nick Carey and Jane Sutton; Editing by W Simon and Grant McCool)