Emergency crews were nearing the end of their search for survivors in the remnants of an Oklahoma City suburb where a huge tornado flattened homes and demolished a primary school.
Authorities lowered the death toll from initial estimates of 51 to 24. Fire Chief Gary Bird said he was “98% sure” there were no more survivors or bodies to recover under the rubble in Moore.
He said every damaged home had been searched at least once and he was hopeful the work could be completed by nightfall, though heavy rains slowed efforts.
Mr Bird said no additional survivors or bodies have been found since Monday night. The death toll included at least nine children. More than 200 people were treated at local hospitals.
“We will rebuild and we will regain our strength,” said Governor Mary Fallin, who went on a flyover of the area and described it as “hard to look at”.
The ferocious storm, clocking winds of up to 200mph, ripped through the region, known as Tornado Alley, reducing homes to piles of splintered wood. Less than 1% of all tornadoes reach such wind speed.
Oklahoma City mayor Mick Cornett called it the “storm of storms”.
In Washington, President Barack Obama pledged urgent government help.
“In an instant, neighbourhoods were destroyed, dozens of people lost their lives, many more were injured,” Mr Obama said.
“Among the victims were young children trying to take shelter in the safest place they knew their school.”
The storm left scores of blocks barren and dark in Moore, a community of 41,000 people 10 miles south of Oklahoma City.
New search-and-rescue teams moved at dawn yesterday, taking over from the 200 or so emergency responders who worked all night. A helicopter shined a spotlight from above to aid in the search.
Other search-and-rescue teams focused their efforts on Plaza Towers Elementary, where the storm ripped off the roof, knocked down walls and turned the playground into a mass of twisted plastic and metal as students and teachers huddled in hallways and bathrooms.
Several students were pulled alive from under a collapsed wall and other heaps of mangled debris. Rescue workers passed the survivors down a human chain of parents and neighbourhood volunteers.
The tornado then headed towards another school, Briarwood Elementary, where children cowered as the roof collapsed.