As the Louisiana floodwaters swallowed Lyn Gibson’s two-storey home, she hacked away on a hole near the roof, desperately trying to get to safety. She used a saw, a screwdriver and her feet, knocking her way through wood, vinyl and sheet rock.

“I just kept picking and hitting and prying until I could get a hole big enough,” the slightly-built, 115-pound woman said. “I would saw for a while. I’d kick at it for a while.”

Eventually, Ms. Gibson made it out of her Tangipahoa Parish home with her dogs, and they were all rescued by National Guard soldiers on a boat. It was one of thousands of rescues after a deluge dropped more than a foot of rain on parts of southeast Louisiana, submerging roads, cars and homes.

At least three people were killed across the state, and the rescues were continuing late Saturday, including missions by crews in high-water vehicles who went car to car to pluck motorists from a flood-soaked interstate.

Maj. Doug Cain from the Louisiana State Police said about 125 vehicles were stranded on a seven-mile stretch of Interstate 12 near Baton Rouge and the occupants were being taken to safety.

In one dramatic moment earlier in the day, two men on a boat pulled a woman from a car that was almost completely underwater, according to video by WAFB. The woman, who is not initially visible on camera, yells from inside the car: “Oh my god, I’m drowning.”

One of the rescuers, David Phung, jumps into the brown water and pulls the woman to safety. She pleads with Mr. Phung to get her dog, but he can’t find it. After several seconds, Mr. Phung takes a deep breath, goes underwater and resurfaces with the small dog. Both the woman and dog appeared to be OK.

Louisiana Gov. John Bel Edwards declared a state of emergency, calling the floods “unprecedented” and “historic.” He and his family were even forced to leave the Governor’s Mansion when chest-high water filled the basement and electricity was shut off.

“That’s never happened before,” said the Governor, whose family relocated to a state police facility in the Baton Rouge area. Rivers and their tributaries swelled and bulged beyond their banks.

In this aerial photo over Robert, Louisiana, rescuers and evacuees stand on U.S. Route 190 after heavy rains inundating the region on Saturday. Louisiana Gov. John Bel Edwards says more than 1,000 people in south Louisiana have been rescued from homes, vehicles and even clinging to trees as a slow-moving storm hammers the state with flooding.