The death toll for the Missouri tornado rose to 117 today, making it single deadliest twister in the United States for 60 years.
Before the disaster that swept through the town of Joplin, the previous worst killed 116 people in Flint, Michigan, in 1953.
More deaths have resulted from outbreaks of multiple tornadoes. On April 27, a pack of twisters roared across six Southern states, killing 314 people, more than two-thirds of them in Alabama.
Sunday’s tornado ripped through the heart of Joplin, a working-class city of 50,000 people, slamming straight into St. John’s Regional Medical Centre. The hospital confirmed that five of the dead were patients – all of them in critical condition before the tornado hit. A hospital visitor was killed also.
The tornado destroyed possibly “thousands” of homes, Fire Chief Mitch Randles said. It levelled hundreds of businesses.
President Barack Obama is to visit Missouri on Sunday to meet people whose lives have been turned upside down by the twister. He vowed to make all federal resources available for efforts to recover and rebuild.
“The American people are by your side,” he said. “We’re going to stay there until every home is repaired, until every neighbourhood is rebuilt, until every business is back on its feet.”
Craig Fugate, director of the Federal Emergency Management Agency, said Mr Obama has declared a disaster in the area, which means residents are eligible for his agency’s assistance.
“We’re here for the long haul, not just for the response,” Mr Fugate said.
Much of Joplin’s landscape has been changed beyond recognition. House after house was reduced to slabs, cars were crushed like drink cans and shaken residents roamed streets in search of missing family members.
The danger was by no means over. Fires from gas leaks burned across city. The smell of ammonia and propane filled the air in some damaged areas. And the forecast looked grim.
The April tornadoes that devastated the South unspooled over a three-day period starting in the Plains. The Storm Prediction Centre in Norman, Oklahoma, said a repeat could be setting up.
“This is a very serious situation brewing,” centre director Russell Schneider said.