An apparent tornado tore through a section of St. Louis' Lambert Field on Friday, lifting the roof off a concourse, injuring several people and forcing the airport's closure.

Planes were diverted to other locations as emergency crews probed the debris for more wounded. Mayor Francis Slay said Lambert would be shut down "indefinitely."

The storm lifted the roof off Concourse C and sent plate glass flying everywhere. Four people were taken to the hospital with minor injuries after glass shattered as the storm hit, airport spokesman Jeff Lea said. An unspecified number of others were treated at the scene for cuts blamed on flying glass.

"We have all hands on deck here," Slay said, noting that responders have included a cadre of workers from the city and county. "This is something we're putting a lot of attention to."

Passengers from at least two planes were stranded briefly on the Lambert tarmac because of debris but were later taken away by buses. An Air National Guard facility at the airport was reportedly damaged.

The airport's main terminal sustained the most damage. Airport director Rhonda Hamm-Niebruegge said roughly half of that structure's windows were blown out, sending glass and rain into that building. Elsewhere on the property, trees were toppled and power lines downed, further limiting access to the airport even hours after the storm left its destruction.

"We're fortunate we didn't have larger (numbers) of injuries," she said.

Pieces of twisted metal lay outside the terminal, the remains of a fierce line of storms that struck central and eastern Missouri. Unconfirmed tornadoes were reported in several counties in the St. Louis area, and thousands lost power.

In the suburbs of Maryland Heights and New Melle, storms caused damage to several dozen homes. There were no immediate reports of major injuries. Some playground equipment in New Melle was left in a twisted heap by the storm that also tore up roofs and ripped off siding.

Damage, possibly from a tornado, was also reported at several towns near the airport _ Bridgeton, St. Ann, Ferguson and Florissant. Interstate 270 in that area was closed. Trees and power lines were down. A tractor-trailer was sitting on its end.

St. Charles County Sheriff's Lt. Craig McGuire said there were early reports of at least 20 homes damaged in the county.

"It was pretty wicked," he said.

In downtown St. Louis, Busch Stadium officials hurriedly moved Cardinals fans to a safe area as tornado sirens blared. The game with the Cincinnati Reds was delayed for hours but later resumed.

The utility company Ameren Missouri reported more than 47,000 power outages, with another 7,000 reported in Illinois.

At Lambert, installation and roofing tile was strewn about the inside and outside of one terminal. Large, plate-glass windows were blown out, at times left lying on the exterior walkways. A shuttle was teetering precariously from the top level of a parking garage.

Dianna Merrill, 43, a mail carrier from St. Louis, was at Lambert airport waiting to fly to New York with a friend for vacation. She said her flight had been delayed by weather and she was looking out a window hoping her plane would pull up. But the window suddenly exploded.

"Glass was blowing everywhere. The ceiling was falling. The glass was hitting us in the face. Hail and rain were coming in. The wind was blowing debris all over the place," she said. "It was like being in a horror movie. Grown men were crying. It was horrible."

Merrill said she felt lucky to be alive and that airport workers quickly moved people to stairwells and bathrooms to get them out of harm's way.

St. Louis County Police Chief Tim Fitch, who was at the airport when the storm was closing in, said he saw gawkers watching the weather outside as the tornado sirens blared. Moments later, they hastily scrambled inside the building and sought shelter in a restroom.

"About the time we came into the building, the doors blew off," he said. "Literally 10 seconds later, it was over. It's amazing to me more people weren't hurt."

In Maryland Heights, a police dispatcher said a tornado hit the area, damaging homes and power lines. The dispatcher, who refused to give her name, said several officers were out dealing with reports of gas leaks and downed trees that were blocking roadways.

The department said it was unclear if there were any injuries.

The city's community center was being opened as a shelter Friday night for residents affected by the storm.

"It looks like we probably had a couple touchdowns around Maryland Heights," said Mary Vaughan, director of parks and recreation for the city. "We got some damage. I don't even know all of it."

A few residents were already at the center, and she expected more to come in later in the evening.

"We have electricity, and everything's fine," Vaughn said. "We have heat and air. We'll be here as long as we need to be."