A monstrous tornado up to a mile wide roared through the Oklahoma City suburbs, flattening entire neighbourhoods with winds up to 200mph, setting buildings on fire and landing a direct blow on a school.
The storm laid waste to scores of buildings in Moore, south of the city. Street after street of the community lay in ruins, with heaps of debris piled up where homes used to be. Cars and lorries were left crumpled on the roadside.
The National Weather Service issued an initial finding that the tornado was an EF-4 on the enhanced Fujita scale, the second most-powerful type of twister.
In video of the storm, the dark funnel cloud could be seen marching slowly across the green landscape. As it churned through the community, the twister scattered shards of wood, pieces of insulation, awnings, shingles and glass all over the streets.
Volunteers and first responders raced to search the debris for survivors.
At Plaza Towers Elementary School, the storm tore off the roof, knocked down walls and turned the playground into a mass of twisted plastic and metal. Several children were pulled alive from the rubble. Rescue workers passed the survivors down a human chain to a triage centre in the car park.
James Rushing, who lives opposite, heard reports of the approaching tornado and, thinking he would be safer there, ran to the school, where his five-year-old foster son Aiden is a pupil. "About two minutes after I got there, the school started coming apart," he said.
The pupils were placed in the restroom.
Police captain. Dexter Nelson said downed power lines and open gas lines posed a risk in the aftermath of the system.
The same suburb was hit hard by a tornado in 1999. That storm had the distinction of producing the highest winds recorded near the earth's surface - 302mph.