A monstrous tornado up to 1.6 kilometres wide has roared through the Oklahoma City suburbs, killing 10, flattening entire neighbourhoods, setting buildings on fire and landing a direct blow on a primary school.

51 people were confirmed killed in a tornado that struck the suburb of Moore, while
hospitals were treating nearly 60 injured, including more than a dozen kids.

The deaths were confirmed by the Oklahoma City medical examiner’s office.

The storm laid waste to scores of buildings in Moore, south of Oklahoma. Block after block of the community lay in ruins, with heaps of debris piled up where homes used to be.

Cars and trucks 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.

The National Weather Service said the tornado had winds of up to 320km/h.

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 parking lot.

James Rushing, who lives across the street from the school, heard reports of the approaching tornado and ran to the school, where his five-year-old foster son, Aiden, attends classes. Rushing believed he would be safer there.

“About two minutes after I got there, the school started coming apart,” he said.

The students 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 ever recorded near the earth’s surface – 486 kph.

For more details visit the Herald’s interactive tornado page here