A tornado destroyed dozens of homes and businesses in this small Mississippi community early Thursday, injuring 20 people and flattening a church.

The fierce storm system also scattered thunderstorms across the South as it churned eastward, leaving a trail of ripped-up rooftops, shattered mobile homes, and downed power lines and trees.

Mayor Jimmy Clyde in the south-central town of Magee said stunned residents were still surveying the destruction from a pre-dawn twister that smashed through dozens of homes, apartment duplexes and even toppled a church and cemetery tombstones.

"This is like reliving Hurricane Katrina all over again, and that's no fun," Clyde said as office phones rang constantly with reports of storm-damaged neighborhoods and lost power and water service. "We got hit back then, and we've really been hit now."

Power blackouts affected tens of thousands of Louisiana residents, and authorities reported damage to some Alabama homes. Georgia residents braced for potentially heavy rains.

Mississippi's governor declared a state of emergency in Simpson County where Magee is located.

Stephanie Malley, 35, cried as she looked at the shell of her home, its roof gone. She awoke when flying debris hit her in the back. She grabbed her 11- and 13-year-old sons and pulled them into a bathroom.

"We stayed in the bathroom for a long time until everything started coming down," Malley said.

Nearby houses were marked with red spray paint to show that emergency workers who dug through the rubble didn't find any injured or dead residents.

Members of the 100-year-old church stepped around the red brick rubble and walked through a cemetery where tombstones were knocked to the ground. A white church van was overturned.

There were still plans to hold Sunday services in the parking lot, however.

"Our church is still here, because our church is the people, but the building is gone," said member Charlene Loyd.

In Baton Rouge, Louisiana, the roof over Louisiana State University's $3.1 million indoor football practice field was damaged overnight by a passing storm.