(CNN) -- Chainsaws wailed Thursday in Granbury, Texas, as residents began to clear fallen trees and whittle down the mounds of household goods strewn across the landscape, a testament to the ferocity of the previous night's tornadoes.
Rescue crews searched for seven people missing after the tornadoes struck this town in North Texas, killing at least six.
"One second you could see the whole roof collapse, and you could see the twister just there, basically," one man told CNN affiliate KTVT. "It was horrible."
He and his family of five had crowded into the bathroom for shelter when the storm hit, he said.
"We were just watching the hail go by and then it just happened in the blink of an eye," a woman said.
Nearby, a water heater lay on its side; an upside-down car, its windows shattered and its silver skin crumpled, lay helpless in the dirt. A wheelchair lay in pieces a few feet away.
Video shot from a helicopter showed rafters still intact, but the roofs they supported were gone.
"We're still working to identify people," Hood County Sheriff Roger Deeds told reporters about the fatalities: four women and two men.
Deeds said search and rescue operations to find survivors "are pretty much winding down."
"We're going to keep on looking," Deeds added. "We're not going to give up until every piece of debris is turned over."
It was not clear whether the toll would rise. Rescuers had walked through the hardest-hit subdivision in the city of Granbury "over and over and over again," Deeds said earlier in the day. "I'm confident we haven't left anybody behind, but we're still checking."
Granbury is 30 miles southwest of Fort Worth.
The deaths occurred in a Habitat for Humanity neighborhood of about 110 homes -- most of which were destroyed -- called the Rancho Brazos subdivision, the sheriff said. That is where the missing were last seen, too, he said.
People whose lives had been hit by the twisters were asking to get back to their homes, but the sheriff said he wasn't convinced it was safe for civilians to be in the area yet.
Three people were taken to an area hospital, and 13 others were taken to hospitals in the Dallas-Fort Worth metroplex, he said.
An estimated 19 buildings were destroyed in Hood County; 17 incurred major damage and 30 minor damage.
Officials said 17 mobile homes also were destroyed.
At least 12 tornadoes touched down overnight in the area, the National Weather Service said. A survey team said it found damage indicating an EF4 tornado had struck. That is the second-most severe classification on a scale of zero to five.
Several of those tornadoes struck Cleburne, about 30 miles east of Granbury.
"I was actually standing outside on my front porch and watched (a) tornado come across," Robert Barnett told CNN affiliate WFAA. "I've seen tornadoes before -- I've chased them -- but I've never seen one like this. It freaked me out."
Another resident said he thought the storm had passed but was wrong.
"I went back outside and saw stuff flying by and said 'It's here! Let's go!'" Darrin Vasquez told the station. He lost part of the roof on his home and when rain flooded in, a ceiling collapsed.
WFAA said at least 12 homes lost their entire roofs.
In nearby Ellis County, a suspected tornado knocked out power in the city of Ennis about midnight, said Steve Howerton, city manager.
"Several buildings in the downtown historic district have been seriously damaged," he said.
"There are a lot of traumatic injuries," said Donna Martin, a worker at a local veterans' organization. "My husband told me that a car was lifted in the air. It just came in and hit so fast."
B.B. French, who lives on a canal three miles from where the worst of the damage occurred, said she was lucky.
"We had extreme winds," the 71-year-old resident said in a telephone interview. "And then the sirens went off and then I got inside."
As lightning flashed and rain poured, she watched from inside her home as two mallards lay on the pavement. "They just laid down on the sidewalk until the hail came, and then they were smart enough to waddle over and get underneath the roof" of her boat deck.
After the storm passed, she went outside to find that her neighbor on one side had lost a few shingles from his roof; on the other side, a neighbor had lost a couple of shutters; but her house was unscathed.
"It really is just luck," she said.
CNN's Dave Alsup, Chandler Friedman and Mayra Cuevas contributed to this report.