Video: Storms unleash deadly tornado on Alabama
A mile-wide tornado has ripped through the town of Tuscaloosa, Alabama, decimating homes and businesses, killing 15 people and bringing the death toll across the American South to at least 64.
Governor Robert Bentley of Alabama declared a state of emergency after 25 were killed by storms on Wednesday alone. That was before the tornado hit Tuscaloosa, where 100 were said to have been injured. Another 11 people were killed in Mississippi, two in Georgia and one in Tennessee.
President Barack Obama later announced a state of emergency in Alabama, freeing up federal agencies to lend assistance.
The Tuscaloosa tornado was one of several that hit Alabama. It tore through the city after 5pm, sweeping past a major medical centre, the University of Alabama campus and a high school.
Many parts of the state had been on a tornado watch throughout the day, prompting schools, government offices and businesses to close early or shut down. One of the Mississippi dead was a father trying to shelter his daughter at a campsite when he was killed.
Mayor Walter Maddox of Tuscaloosa said that sections of the city had been destroyed. News footage showed paramedics lifting a child out of a flattened home, with many other buildings in the city of more than 83,000 people also reduced to rubble.
"The city experienced widespread damage from a tornado that cut a path of destruction deep into the heart of the city," Mr Maddox said in a statement.
Barack Obama released a statement saying it could be days before the full extent of the damage from the storm is known.
"Michelle and I extend our deepest condolences to the families of those who lost their lives because of the tornadoes that have swept through Alabama and the southeastern United States," he said.
"Our hearts go out to all those who have been affected by this devastation, and we commend the heroic efforts of those who have been working tirelessly to respond to this disaster."
The storm system was forecast to hit North and South Carolinas next before moving further north-east.
"I'm in my car at corner on McFarland. Milo's Hamburgers isn't there anymore," Tuscaloosa resident Phil Owen told WBMA. "Hobby Lobby [is the] only thing still standing at Woods Square Shopping Centre. Big Lots, Full Moon Barbecue -- piles of garbage where those places were."
In Mississippi, Lieutenant Wade Sharp of the Louisiana state police was killed during a camping trip in a state park when a tree branch fell on his tent. Three other men were also killed by falling fallen trees.
A girl of three died in Mississippi on Tuesday after a tree fell on her house. Another 10 people died in Arkansas because of flooding and a tornado.
Wendy Pesnell lost her home when a tornado hit after 6 am on Wednesday. She told ABC News: "It's just kind of like. ... It makes you stop and think you know, 'Wow.' You know, we're here one minute and be gone the next."
George Bearden said the tornado hit so fast that he and his family had no time to run. "Pieces of our house are scattered across two countries," he said. "But we survived it."