President Barack Obama on Friday joined shocked Americans sifting through the wreckage from the worst US tornadoes in nearly 80 years, which claimed at least 324 lives in the American south.
"We're going to make sure that you're not forgotten," Obama said on a visit to Tuscaloosa after meeting victims whose homes were literally blown to bits. "I've never seen devastation like this. It is heartbreaking."
Tornadoes claimed the lives of 324 people -- making it the third-deadliest tornado tragedy in US history, and the worst to strike the United States since 332 people were killed March 21, 1932.
The worst tornado outbreak in the United States, in March 1925, left 747 people dead.
Entire blocks were obliterated in Tuscaloosa, a city of about 90,000 people, where Obama touched down to see the destruction first-hand, meet with Alabama Governor Robert Bentley and reassure residents in the aftermath of the worst US natural disaster since Hurricane Katrina in 2005.
He and First Lady Michelle Obama shook hands and hugged distraught residents, with the president pledging to help Tuscaloosa and dozens of other battered cities and towns across the US south.
Outside Tuscaloosa, Obama visited the tornado-battered Holt elementary school, which is being used as a distribution center for aid supplies. He spoke to the school principal, aid workers and storm survivors.
"Thank you for helping, and I'm glad you're OK," he told them.
The principal, Debbie Crawford, told Obama that she and the school nurse "have been here for 48 hours" and had slept just four hours.
Obama spoke as the first estimates about the magnitude of property damage emerged, with catastrophe modeling firm EQECAT saying the tornadoes could result in between $2 billion and $5 billion in insurance costs.
"We can't bring those who have been lost back, they are alongside God at this point," but Obama pledged "maximum federal help" to cope with massive property damage and recovery costs.
The number of confirmed tornado-related deaths increased Friday to 228 in Alabama, the worst-hit state; to 34 in Mississippi; and to eight in Arkansas, officials said.
Aside from those states, the twisters left 34 dead in Tennessee, 15 in Georgia, and five in Virginia, according to state officials.
Recalling the more recent horror of Hurricane Katrina in 2005, families picked through the remains of homes, businesses and schools, bearing witness to scenes of devastation more common in war zones or after earthquakes.
The storms have wreaked the most damage in some of the nation's poorest districts already hit hard by the economic downturn.
Two Mexican brothers, Hernando and Miguel Jimenez, were helping to deliver food and water to church members stricken by the tornadoes.
"It's terrible what has happened. Perhaps the only good thing is that we will need to rebuild the town and that could give work to the unemployed," said Hernando.
In a bid to maintain order, Tuscaloosa Mayor Walter Maddox ordered a curfew, lasting from dusk until 8:00 am, for the second night. A police precinct was among the buildings damaged.
A sign on one door bluntly warned potential intruders what awaits them: "I will shoot you."
In addition to the deaths in Alabama, there were more than 2,000 injured and up to a million people left without power. Restoration of electricity could take several days.
States of emergency were declared from central Oklahoma to Georgia on the eastern seaboard, and governors called out the National Guard -- including 2,000 troops in Alabama -- to help with the rescue and clean-up operations.
"We had a major catastrophic event here in Alabama with the outbreak of numerous long-track tornadoes," said Governor Bentley.
In neighboring Mississippi, which suffered more than 30 casualties, Governor Haley Barbour described "utter obliteration" in the town of Smithville, which had 13 deaths and several people missing.
"Search and rescue continues," Barbour said, adding that he is "praying for the best but we're going to be preparing for the worst."
As the long day dragged on, rescue workers battled to find missing people and try to rescue survivors still trapped in the rubble of their homes.
Many homes looked like they had been blown inside out, with the walls torn down and furniture spilling into the street.
In a parking lot at the University of Alabama in Tuscaloosa -- where 36 people were confirmed dead -- tornadoes left behind 20 smashed cars, many of them piled on top of one another.
"I don't want to think now in how much I lost," Robert Mitton told AFP. "I hope we can get some help from the government. I live very close, my house is very damaged, but my family is fine."
Owen Simmons, who works in a furniture store, pointed to a black cross and a zero below painted on the side of his house.
"It means that the rescue team has already checked my home and they found no victims. That's what really matters."
It was also a dark day for Birmingham, Alabama's largest city with more than a million residents. Mayor William Bell spoke of "whole neighborhoods of housing, just completely gone. Churches, gone. Businesses, gone."