MORE than 230 people have been killed by hundreds of tornadoes raging across the south of the United States.
Entire towns were destroyed as six states were struck by the region's most devastating outbreak of storms for almost 40 years.
One tornado captured on video measured a mile wide -- 20 times larger than a typical tornado.
A state of emergency was declared by the governors of Alabama, Arkansas, Georgia, Kentucky, Mississippi, Missouri, Oklahoma and Tennessee as the death toll was expected to rise.
The National Weather Service said it had received 137 tornado reports early yesterday, bringing the total counted in the region since last Friday to 300.
Alabama, one of America's poorest states, suffered the worst. More than 131 people died -- 36 in the city of Tuscaloosa alone. Walter Maddox, the mayor, said the city had been obliterated.
"I don't know how anyone survived," said Mr Maddox. "There are parts of the city I don't recognise and I've lived here my entire life."
James Sykes, a resident, described watching a "silent monster" suck up the city's streets.
"It was full of lightning, devastating everything," he said.
Dozens of businesses and emergency service buildings were destroyed. A million people were left without power.
"We had a major catastrophic event here in Alabama," said Robert Bentley, the state governor. "We have had major destruction."
Storms also caused the Browns Ferry nuclear power plant near Huntsville, Alabama, to lose power.
Officials described the incident as a low-level emergency and said it was under control.
In Mississippi, at least 32 people were killed; another 30 were reported dead in Tennessee; 11 in Arkansas; 13 in Georgia; seven in Virginia; and three in Missouri. President Barack Obama, who promised swift assistance from the National Guard and will visit Alabama today, said: "Our hearts go out to all those who have been affected by this devastation." He praised the "heroic efforts" of those who were responding to the disaster by clearing wreckage and searching for victims.
People throughout the south were trapped after fallen trees and flooding left large areas impassible.
Tim Holt, a hotel worker in Ringgold, Georgia, said: "Our town is in pieces. It's an 80pc loss."
Birmingham, the largest city in Alabama, was also struck.
Samantha Nail, who lives in one of its suburbs, described watching brick houses being swept away.
"We were in the bathroom holding on to each other and holding on for dear life," she said.
"If it wasn't for our concrete walls, our home would be gone like the rest of them."
The storms are believed to be the deadliest natural disaster in the United States since Hurricane Katrina, which killed more than 1,800 people in Louisiana in 2005.
It has also been the deadliest tornado system since the "super outbreak" of April 1974, when 310 people were killed in 148 tornadoes across 13 states.
Further heavy rain and high winds are expected tomorrow, with 21 states throughout the country receiving warnings of severe weather. (© Daily Telegraph, London)