Published: Mar 09, 2011 5:34 PM EST
Updated: Mar 09, 2011 2:34 PM EST

MOBILE, Ala.- Winds whipped by a line of severe weather tore roofs off buildings, overturned cars and injured people as the system trudged across the Southeast on Wednesday.

An apparent tornado heavily damaged several buildings and hurt people near Mobile in southwest Alabama, hours after three tornadoes were reported to the west in Louisiana. The system also dumped seven inches of rain in parts of Mississippi and spawned thunderstorms in Tennessee that ripped off part of a school's roof.

In Alabama, Mobile County Emergency Management Agency operations officer Donald Leaf said it was unclear how many people were hurt by the apparent twister.

Ambulances, police cars and fire trucks with flashing lights descended on the Theodore area near Mobile after the storm struck about 8:45 a.m. CST, overturning vehicles, nearly demolishing a gas station, knocking down power lines and causing ammonia and natural gas leaks.

Evelyn Thibeault said she saw a twister go by her business, Theodore Mail Ship and More.

"My front door flew open and a plant flew across the floor. Everything just turned white. BP is just gone. It's horrible," said Thibeault, breathing hard during a telephone interview. "It hit a hardware store, a little country music place they have. We're all still nervous and shook up."

The Louisiana tornadoes touched down early in the morning on the heels of the Mardi Gras season, which ended Tuesday night.

The New Orleans metropolitan area was under a flash flood warning as downpours ranging from 1 to 3 inches flooded some streets.

Forecaster Mike Shields said one tornado touched down about 10 miles southwest of Bush in St. Tammany Parish around 5:20 a.m. - injuring one person, damaging a house, destroying a trailer and knocking down trees. Emergency officials said the woman suffered a cut on her head.

Firefighters in Lacombe reported a twister that took the roof off a house just before 5 a.m. And the weather service said a meteorologist reported a tornado on the north side of Kenner near Lake Pontchartrain shortly after 6 a.m. No damage was reported.

In Tangipahoa, authorities used boats to evacuate about 50 families from a mobile home park after heavy rains caused a creek to overflow.

A thunderstorm in eastern Tennessee tore a section of roof from Camp Creek Elementary School on Wednesday morning, The Greeneville Sun reported. No injuries were reported and there were no children at the school yet.

Some buildings in Mississippi have also been damaged, but no deaths or injuries were immediately reported in that state.

Flash flood warnings were in effect in southeast Mississippi, and roads in several counties were flooded.

"Flooding is going to persist in some areas for a few days as water filters down into the larger rivers and waterways," said Daniel Lamb, a meteorologist with the National Weather Service in Jackson.

(Copyright 2011 by The Associated Press. All Rights Reserved.)