A severe storm that struck the St. Louis area left homes flattened in suburbs around the main airport, which was closed for most of Saturday after being hit by a tornado.

Debris from splintered homes covered the ground in neighborhoods around the city, while topped trees and overturned cars littered lawns and driveways. From the air, one home looked like a dollhouse that had had its roof lifted off.

The tornado that roared through the area Friday night didn't seriously injure anyone.

"It almost feels like a little bit of divine intervention when you look at the devastation," said Gov. Jay Nixon, who flew over the area to survey the damage.

The severe storm damaged a St. Louis building of the Air National Guard. (Sarah Conard/Reuters)

Nixon said President Barack Obama pledged federal assistance Saturday during a phone conversation. Some 750 homes in the St. Louis region were damaged, and less than 100 were uninhabitable, the governor said.

Cleanup swung into full gear Saturday. With the din of chain saws and pounding hammers in the background, homeowners sifted through wreckage while crews scrambled to restore power to the 26,000 customers still without it.

Roofers were going door-to-door, offering free temporary repairs. Insurance adjusters arrived in trucks to help their clients. Neighbours helped each other pull trees from roofs and pick up metal pieces, glass and splintered limbs from yards.

"It's crazy — like something you'd see in a movie," 27-year-old Tim Kreitler said as he helped a neighbour clean up.

Airplanes severely damaged

At Lambert airport, workers boarded up windows and swept up glass in the main terminal, where the twister had torn off part of the roof and blown out half of the large, plate-glass windows.

The airport reopened Saturday night for a handful of arriving flights, and officials expected around 70 per cent of the scheduled arrivals and departures to go on as planned early Sunday. The damaged concourse was likely to remain closed for up to two months.

"We're not going to have the prettiest airport tomorrow, but we will have an operating airport," airport director Rhonda Hamm-Niebruegge said.

A spokeswoman for Southwest Airlines said one of its planes was damaged when the wind pushed a conveyor belt for loading baggage into it. Five other planes on the ground when the tornado hit were OK, spokeswoman Marilee McInnis said. Southwest — the biggest carrier at Lambert, with 85 departures a day — cancelled all St. Louis flights through 4 p.m. CT Saturday.

American Airlines, which operates out of the heavily hit main terminal, said four of its planes were damaged, two of them significantly. Crosswinds of 130 km/h buffeted one plane that was taxiing in from a landing when the tornado hit, and that plane was being checked for possible damage to its landing gear, spokesman Ed Martelle said. American cancelled 51 flights on Saturday, five dozen on Sunday and its first seven Monday morning.