Residents of the southern United States are coping with the aftermath of the country's deadliest tornado disaster since the Great Depression.
The death toll from Wednesday's storms reached 337 across seven states, including 238 in Alabama, making it the deadliest US tornado outbreak since March 1932, when another Alabama storm killed 332 people.
Hundreds if not thousands of people were injured on Wednesday - 990 in Tuscaloosa alone - and as many as a million Alabama homes and businesses remained without power.
"It's just barren," Josh Mays, a tornado victim, said. "It sounded like at least a thousand trains up in the sky."
Barack Obama, the US president, who visited Tuscaloosa on Friday, said: "We just took a tour and I have got to say, I have never seen devastation like this."
"While we may not know the extent of the damage for days, we will continue to monitor these severe storms across the country and stand ready to continue to help the people of Alabama and all citizens affected by these storms," he said.
Obama told the victims that the federal government is "going to make sure you are not forgotten".
The president's action makes federal funding available to affected individuals in storm-ravaged areas.
Assistance can include grants for temporary housing and home repairs, low-cost loans to cover uninsured property losses, and other programmes to help individuals and business owners recover from the effects of the disaster.
Some of the worst devastation occurred when a 1.6km-wide tornado slammed into Tuscaloosa, home to 95,000 people, killing at least 37 people including some students.
Al Jazeera's John Terrett, reporting from Tuscaloosa in Alabama, said people in the area are very concerned there are people still underneath the wreckage who have not been found.
"There is a tremendous sense of community here and the community does appear to be pulling together in a way I have not seen anywhere in the world," he said.
Tornadoes struck with unexpected speed in several states. Four people died in Bledsoe County, Tennessee, but a family survived being tossed across a road in their modular home, which was destroyed.
In Tuscaloosa and other cities, looters have been picking through the wreckage to steal what little the victims have left.
Overwhelmed Tuscaloosa police imposed a curfew and received help from National Guard troops to try to stop the scavenging.
Along their flattened paths, the twisters blew down police and fire stations and other emergency buildings along with homes, businesses, churches and power infrastructure.
Tuscaloosa's emergency management centre was destroyed, so officials used space in one of the city's most prominent buildings - the University of Alabama's Bryant-Denny Stadium - as a substitute before moving operations to the Alabama Fire College.
Also wiped out was a Salvation Army building, costing Tuscaloosa much-needed shelter space. And that's just part of the problem in providing emergency aid, said Sister Carol Ann Gray of the local Catholic Social Services office.
Tornadoes are a regular feature of life in the US' South and Midwest, but they are rarely so devastating.