WAVERLY, Tenn. — David Allen was inside his downtown Waverly home with his 84-year-old mother when an air conditioning unit floated by. That is when he knew they should flee.

They made it as far as the porch before, Allen said, water slammed into the door frame, as record-breaking rain and flash flooding swept through the area. For three hours, he clung to the porch and held tight to his mother, who is now safe in Clarksville, Tenn., as water gushed around them. Rescue crews were nearby, but they couldn’t reach the house while the water was rushing rapidly.

“I grabbed her and held on,” said Allen, 48. “There was nobody that could get to us. She can’t swim.”

Two days after a torrent of water ravaged parts of Middle Tennessee, what’s left in its wake is a twist of wreckage. Abandoned cars and entire sheds are piled up on a bridge’s guardrails, swept up by water that rose over the roadway. Mud and debris coat the streets. Wet furniture dots the perimeter of homes.

At least 21 people were killed, authorities said Monday morning. Twenty of those fatalities were in hard-hit Waverly, a town of more than 4,000 people about 60 miles west of Nashville. Authorities said crews are searching Waverly and looking throughout Humphreys County for the missing.

Local officials said Monday afternoon that they believe fewer than 10 people are still missing, and the search for victims could last days.

Rescue teams searched on Aug. 23 for dozens of people believed missing in Tennessee after record downpours and flash flooding left at least 21 dead. (Reuters)

Some officials stressed that Monday’s operations were shaping up as more of a recovery effort.

“The likelihood they will find somebody alive that they didn’t know about, that diminishes day by day,” Dean Flener, a spokesman for the Tennessee Emergency Management Agency (TEMA), told The Washington Post.

Humphreys County Emergency Management Agency spokeswoman Grey Collier said initial rescue crews had to be very cautious in searching through debris, but they are now able to put more equipment in the water and are using cadaver dogs to search for missing residents. She said that it may look as though cleanup has begun but that authorities are still looking for survivors.

In social media posts, family and friends made desperate pleas for information about loved ones whose whereabouts were unknown, sharing recent photos to help identify anyone spotted. Others updated their posts with relief when their loved ones were found alive. Public safety officials posted a list of names on Facebook of those reported missing and urged people to call if they knew of any who were found safe.

Three shelters have been set up in Waverly for the displaced. Flener said 93 people stayed in shelters Sunday night.

According to the Humphreys County Emergency Management Agency, 2,000 homes were without power as of Monday morning.

Survivors on Monday recounted the horror that took place in what seemed a matter of moments.

Luke and Lindsey Coplin of Memphis arrived at an RV resort in Bon Aqua, Tenn., southeast of Waverly, on Friday evening for a relaxing getaway with their two children, ages 7 and 10. The weather was clear when they went to bed. By 6 a.m., they couldn’t see the bottom step of their camper as they fled through the front door.

Lindsey Coplin said she rushed her 7-year-old into their SUV while her 10-year-old followed, the water already waist-deep for the kids. They scrambled to get to higher ground.

“It all happened in six minutes,” Lindsey Coplin said.

Luke Coplin said he and others tried to help an older woman who had been swept away and was found clinging to a low-hanging limb, “fighting for her life” to keep her head above water. They were able to pull her to safety, but they worry she may have broken her arm.

The event was traumatizing, but the family is grateful to have survived.

“I would call this a living nightmare and miracle all at the same time,” Lindsey Coplin said.

In Waverly, Allen stood outside his home with a friend as they tried to pick up what was left of it.

“We try to do the best we can,” said Allen’s friend, 44-year-old Waverly resident Chuck Bumpus. “Mother Nature, she can be a real b----. It’s a bad, bad deal.”

Many said this was not their first flood. Torrential rains and catastrophic flooding also hit the area in May 2010, a storm that killed 18 in Middle Tennessee.

“We’re fighters,” said resident Janet Rice, 53. She said her family’s business had stood for a century — during the 2010 flood, water did not even enter the building. But it was destroyed in this weekend’s flash flood.

“We’ve been through a lot,” Rice said. “But this one? I don’t know.”

Rice said their building split in half — and may have saved at least one life. She described a neighbor who was swept up by floodwaters in town and pulled into the building, surviving by holding on to the edge.

For Mee McCormick, the weekend felt like “a little bit of PTSD from 2010.”

The chef and restaurateur was in Nashville, about 46 miles east of her farm and restaurant, Pinewood Kitchen & Mercantile, when her team called to say that the rain was really coming down. She thought the storm would blow over soon, and she couldn’t afford to shut down for the day.

“After the year we’ve had, I can’t close anymore,” she said.

Conditions only worsened. River waters rose, and her team became trapped in the area as “Pinewood became an island.”

She said the floods brought an “insane amount of damage” to the farm, on which the restaurant relies. She has to shut down for now, leaving about 20 employees out of work.

“Nobody in my restaurant can work this week. They live hand to mouth, and I am responsible for them,” she said.

When the interview began, McCormick said she was resolute: “After the last year, you could tell me anything, and I would just go, ‘Okay, let’s figure it out.’”

But as she described the damage, the emotional toll of another flood, the help she would need to clean up and restart her business this time around, her voice broke. She paused.

“Making a place in the middle of nowhere, somewhere — it just felt good,” she said about her business. But now “I don’t know that I’m coming back.”

“I don’t know if I failed, or if Mother Nature has a plan,” McCormick said. “This is going to continue to happen. We live in a time of extreme weather. … Do I go away? How much more can I sustain emotionally and financially?”

Firozi reported from Washington.

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