(AP) -- Mulester Johnson was at home with relatives in northern Mississippi when a fierce storm that has killed at least six people across the country hit.

The wind tore the back of Johnson's Holly Springs house from its foundation and multiple sheds were missing afterward, he said. Trees rested atop several trucks on his property, and slabs of brick walls were strewn throughout his yard after the storm.

"The chimney is the only thing that saved us really," Johnson, 67, said.

The deadly spring-like storms came Wednesday amid unseasonably warm weather that made the perfect recipe for destructive weather.

Johnson opened the door to what had been a bedroom and looked past his disheveled belongings to clusters of broken trees in the backyard. The room's walls had been blown away.

"This right here is a mess, but I can't complain because we're blessed," he said. Johnson planned on staying with relatives Wednesday night and said no one inside the house was injured.

The storms killed at least three in Mississippi, two others in Tennessee and one in Arkansas before the worst passed Wednesday night.

A 7-year-old boy died in Holly Springs when the storm picked up and tossed the car he was riding in, officials said.

The Mississippi Emergency Management Agency said dozens of people in the state were being treated for injuries.

Agency spokesman Greg Flynn said before dawn Thursday that injuries are "more than 40 for sure, and some of those are quite serious." Some of the injuries included amputations, he said.

A tornado damaged or destroyed at least 20 homes in Clarksdale, Mississippi. Planes at a small airport overturned and an unknown number of people were injured.

"I'm looking at some horrific damage right now," Clarksdale Mayor Bill Luckett said. "Sheet metal is wrapped around trees; there are overturned airplanes; a building is just destroyed."

Television images showed the tornado appeared to be on the ground for more than 10 minutes. Interstate 55 was closed in both directions as the tornado approached, the Mississippi Highway Patrol said.

Along Mississippi Highway 7 close to Johnson's house, headlights from passing cars illuminated downed tree limbs, slabs of plasterboard and wooden beams that had been turned into projectiles when the tornado passed.

Pieces of metal tangled in drooping power lines, dangling precariously alongside the road. The smell of freshly overturned dirt and trees lingered in the air as emergency crews tended to downed lines.

In Benton County, Mississippi, where at least two deaths occurred and at least two people were missing, crews were searching house-by-house to make sure residents were accounted for.

In Arkansas, Pope County Sheriff Shane Jones said 18-year-old Michaela Remus was killed when a tree crashed into her bedroom. The woman and her 1 ½-year-old sister were sleeping in a bedroom of the house near Atkins about 65 miles northwest of Little Rock, when winds uprooted the tree that crashed through the roof. Rescuers pulled the toddler safely from the home.

"It's terrible that this happened, especially at Christmas," Jones said.

In parts of Georgia, including Atlanta, a flood watch was posted through Friday evening as more than 4 inches was expected, the National Weather Service said.

The threat of severe weather just before Christmas is unusual, but not unprecedented, said Greg Carbin, a meteorologist at the national Storm Prediction Center.

Once the strong storms clear out, warm temperatures were expected. Highs in Atlanta and Charlotte, North Carolina, on Christmas Eve were forecast to be in the mid-70s.

___

Associated Press writers Jeff Martin in Atlanta; Claudia Lauer in Little Rock, Arkansas; and Jay Reeves in Birmingham, Alabama; contributed to this report.