AUBURN, Ala. — Ten-year-old Taylor Thornton had just returned from a camping trip with friends to reunite with her family when the tornado hit. When her father went to pick her up from a friend’s house Sunday afternoon, the mobile home was in shambles.

Amid the wreckage, he found Taylor’s body, relatives said.

“Angel from heaven,” Lee Thornton said soon after learning his niece had been killed. “Never did anything wrong.”

Authorities on Monday sifted through the debris searching for other victims of the powerful tornadoes that tore across the Southeast a day earlier, slicing through parts of Alabama, Florida, Georgia and South Carolina. Many survivors were left without homes, packing into shelters and recovering in hospitals.

The worst of it was felt here in Lee County, Ala., where at least 23 people were killed, authorities said, more than doubling the death toll from all tornadoes nationwide last year.

Alabama officials said at least three children were killed, including a 6-year-old and a 9-year-old. As crews continued searching the wreckage, they warned that the death toll could increase. The tornadoes unleashed “catastrophic” damage in Lee County, said Sheriff Jay Jones.

“It looks like someone took a giant knife and scraped the ground,” he said.

Aerial video from Beauregard, Ala., captures the aftermath of tornados that hit the area on March 3. (Robert Ray, Adriana Usero/The Washington Post)

The storm’s deadliest impact occurred in one square mile, Jones said, although some debris was thrown as far as a half-mile. Many of the obliterated homes were concentrated along two rural routes, centering much of the pain in one narrow slice of the state.

Lee County coroner Bill Harris said his office had identified nearly all the victims, but he would not release the names until their next of kin are notified.

“Some of them have lost just about their entire family,” Harris said of the survivors.

The National Weather Service said Monday that the tornado in Lee County had a preliminary EF-4 rating, the second-strongest category, with winds as strong as 170 mph. It was the first tornado of that strength in the United States since an April 2017 twister in Canton, Tex.

Rescuers deployed infrared drones, helicopters and dogs to search for signs of life amid a wide swath of debris, Jones said. And people also rushed to help friends and neighbors whose homes and businesses were destroyed by the powerful winds.

Ashley Riggs said that she took the day off work to search her friends’ homes in Beauregard, Ala., for any undamaged belongings. They had survived the tornado by sheltering in a bathtub, but one was taken to a hospital with a broken leg and another had bruised her shoulders.

Julie Morrison and Eric Sward’s mobile home “blew off the foundation” and “both cars were demolished,” she said. Their son Chris Sward’s mobile home, which was next door, was also destroyed.

“There is nothing where the house sat,” said Riggs, 35. She found some car keys, she said, but could not find a wallet.

Residents had precious few minutes to brace for the storm. The first tornado warning was issued at 1:58 p.m. — five minutes before the initial damage reports in Lee County were received, National Weather Service meteorologist Gary Goggins said in Birmingham.

A second tornado struck 35 minutes later, he said.

The National Weather Service reported Monday that a second strong twister began in Macon County and then moved into Lee.

Scott Fillmer, 48, had sought shelter in his laundry room with his wife, their three cats and a puppy once the emergency warnings began to blare from his phone.

After the deadly tornadoes had passed, the first thing Scott Fillmer noticed was the overwhelming smell of pine trees that littered his front yard in Beauregard, Ala.

When he opened his front door, he found two power lines and a mattress in his driveway. His patio furniture was hanging from the surviving trees. A car bumper had flown into his pasture, and jagged slabs of wood were strewn on the lawn.

He got in his tractor and grabbed a chain saw, and then he saw the rest of it: The leveled mobile homes. The dilapidated buildings missing their roofs.

“You didn’t realize how bad it was until you got on the road,” he said. “Now it looks like it’s one of the worst tornadoes.”

The scene after deadly tornadoes hit the Deep South

March 4, 2019 | Brittney Downs sorts through the remnants of Eric Sward’s home after a tornado destroyed it. Downs, a family friend, was looking for Eric’s wallet. (Kevin D. Liles/For the Washington Post)

President Trump, speaking at the White House on Monday, addressed Lee County and said the federal government “pledged our unwavering support to help you rebuild” after the tornadoes.

“Towns, schools, churches and homes were devastated by tornadoes of a force like we haven’t seen in a long time. Historic,” he said. Trump added of the storms: “Probably nobody made it out of that path; that path was brutal.”

Alabama Gov. Kay Ivey (R) said she had expanded a state of emergency already declared for severe weather. In Georgia, Gov. Brian Kemp (R) followed suit with his own emergency declaration Monday for Grady, Harris and Talbot Counties.

The tornadoes on Sunday were the nation’s deadliest since May 2013, when a category measuring an EF-5 — the strongest category — pummeled Moore, Okla., killing 24 people and injuring more than 200 others, according to the National Weather Service.

There were at least three dozen tornado reports on Sunday as twisters strafed across the Southeastern states.

The damage and debris flitted across state lines, with a billboard from Lee County getting blown clear across the state line into Georgia. One strong tornado narrowly missed Macon, Ga., while another hit Cairo, Ga., where Mayor Booker T. Gainor said more than two dozen homes in the town of about 10,000 had been damaged.

Scott Peake, a 33-year-old storm chaser, was right on the tail of one tornado in Lee County.. He watched it skip across Highway 51, and while a parade of headlights whizzed past him, fleeing the storm, Peake charged toward it, getting about a quarter-mile from its path, he said.

“I was close enough that I could hear the roar,” he said. “It sounded like I was in a waterfall.” Peake has tracked many tornadoes before, but what he saw in Alabama was extraordinary, he said. As he headed south down Highway 51 in his Ford Taurus, he drove past a mobile home park near Beauregard where first responders were just starting to swarm.

“Everything was flattened,” he said, with only one mobile home still standing.

When it was safe to head outside again, Trey Capps went to his family’s business, Capps Sausage, fearing the worst after seeing the news about the storm’s impact. That’s exactly what he found, discovering that the building’s roof was missing and a longtime family home that his great-grandfather built had been leveled. Pecan trees that Capps estimated were at least 100 years old were gone. The home, he said, was not salvageable, a loss that struck him as “unreal.”

“Thank goodness my folks were out of town at the time,” he said.

Flynn, Horton and Berman reported from Washington. Allyson Chiu, Julie Tate, Jason Samenow, Matthew Cappucci and Amy B. Wang in Washington contributed to this report.