Emergency teams spray-painted damaged houses with "X" signs Saturday after checking them for bodies or survivors and crews moved in dump trucks to haul away the wreckage piled up by tornadoes blamed for 12 deaths.
Bystanders were warned not to smoke because of leaking gas while police patrolled to ensure there was no looting.
Emergency officials implemented a dusk-to-dawn curfew for the worst-hit areas, and National Guard soldiers were brought in to patrol.
"If there's tore-up stuff, don't go there," Gallatin Police Chief John A. Tisdale said.
Tornadoes were spotted in about 10 Tennessee counties on Friday, the second wave of deadly storms to hit the state in less than a week, weather officials said. The worst damage appeared to be in Gallatin and other suburbs northeast of Nashville.
Steve Hurt and eight other people survived by taking shelter in a fireproof room with concrete walls atLee Electric Supply Co. in Gallatin.
"You could hear people yelling and screaming outside and the debris hitting the walls," said Hurt, who said one of his co-workers was killed.
One of the tornadoes that hit the area chewed up a path 150 to 200 yards wide and at least 10 miles long, estimated Jimmy Templeton of the Sumner County Sheriff's Department.
Nine people were killed Sumner County and three were killed in Warren County, about 65 miles southeast of Nashville, state Emergency Management Agency spokesman Randy Harris said Saturday. Hospitals admitted at least 60 people with storm-related injuries.
Harris said a preliminary count showed that 700 to 900 homes in Sumner County and another 500 to 700 in Warren County were damaged or destroyed.
"I'm amazed we didn't have more fatalities," said Sonny Briggance, rescue chief for Sumner County's emergency management agency. "Although the number is high, we are still very lucky."
Gov. Phil Bredesen toured the destruction Saturday.
Gallatin resident Dora Freeze said her best friend, Crystal Graves, died not long after she got home from work.
"When I stand here and look at it all, I just can't believe it," Freeze said.
Most people rummaging through the rubble in Gallatin hunted for photographs and other keepsakes; a few looked for pets.
Diesel smoke filled the air as work crews used heavy equipment to clear paths through the debris. Clumps of yellow insulation hung from trees like Spanish moss, and the sound of helicopters, chain saws and trucks created a loud, steady rumble.
Last weekend, thunderstorms spinning out dozens of tornadoes killed 24 people in western Tennessee and four others in Missouri and Illinois.
Nashville Electrical Service reported hundreds of electrical lines down and power outages affecting up to 16,000 customers, mostly in Goodlettsville. The number of customers blacked out was down to 1,100 Saturday, but some people might have to wait a week for their service to be restored, NES spokeswoman Laurie Parker said.
Later Friday and into Saturday, another line of severe thunderstorms rolled through Alabama, Georgia and South Carolina.
The National Weather Service said four tornadoes swept through Georgia. The twisters destroyed businesses, homes and at least one church in the Atlanta area and knocked out power to tens of thousands, authorities said. No deaths or serious injuries were reported.
Several people were injured in Alabama, two by falling trees, but no deaths were reported, officials said Saturday. A store was destroyed in Ohatchee, near Anniston, and homes and apartments were damaged in the Birmingham area. Storms also pounded southern West Virginia, blacking out more than 16,000 customers, utilities said.
One person was injured in South Carolina as three tornadoes touched down around Charleston, the weather service said. One tornado touched down at the Family Circle Cup tennis facility at Daniel Island, damaging banners and a score board and interrupting the tournament's qualifying rounds.
The weather service confirmed that a tornado touched down in southern Kentucky on Friday, destroying or damaging dozens of mobile homes. Four people sustained minor injuries.