(CBS/AP) Tornadoes across four Southern states tore through homes, ripped the roof off a shopping mall and blew apart warehouses in a rare spasm of violent winter weather that killed at least 26 people and injured dozens more.

The twisters that slammed Arkansas, Mississippi, Tennessee and Kentucky were part of a line of storms that raged across the nation's midsection at the end of a day of Super Tuesday primaries in several states. Candidates including Hillary Rodham Clinton, Barack Obama and Mike Huckabee even paused their victory speeches to remember the victims.

The storms killed at least 12 people in Tennessee. Angela Alexander, spokeswoman for Sumner Regional Medical Center, said early Wednesday morning that four people died and several others were injured after severe storms moved through the county northwest of Nashville.

Two have also died in a home near Jackson. Three people were killed when a roof collapsed at the DSC Logistics warehouse in Memphis.

A man was killed in his car in Fayette County and two others died in Hardin County east of Memphis during the wave of storms that began Tuesday.

A suspected twister battered the Hickory Ridge Mall in Memphis. "The ceiling came off, the wind started blowing really hard, it was really gusty," shopper Tyeisha Green told CBS affiliate WREG.

Green had her two young children with her and said all she could do was clutch them and pray. "I was scared, they started to panic, I didn't know what to do but hold onto them."

A spectacular fire erupted at a natural gas pumping station northeast of Nashville that authorities could have been damaged by the storms, and an undetermined number of people were reported dead.

A couple and their 11-year-old daughter were killed in their home after a tornado touched down near the center of Atkins, a community of 3,000 along the Arkansas River in the central part of the state.

"This was an extraordinary night," said Gov. Mike Beebe. "When it's compounded by darkness, that makes it that much more difficult."

An Arkansas State Police dispatcher says multiple car crashes slowed traffic on Interstate 40 near Atkins to a crawl, reports CBS affiliate KTHV in Little Rock. A tractor-trailer reportedly blew over in an eastbound lane of the interstate.

Emergency crews went door to door Tuesday night seeking other possible victims in Atkins, working amid a heavy scent from splintered pines. Power lines snaked along a street, and a deep-orange pickup truck rested on its side. A navy blue Mustang with a demolished front end was marked with spray paint to show it had been searched.

Outside one damaged home, horses whinnied in the darkness, looking up only when a flashlight reached their eyes. On Southeast Second Street, a ranch home stood unscathed across the street from a concrete slab that had supported the house where three people died.

Three adults died outside Greenville, Ky., in the western part of the state, authorities said.

The power was knocked out briefly at a Little Rock convention hall that hosted an watch party for GOP presidential candidate Mike Huckabee, a former Arkansas governor.

"While we hope tonight is a time for us to celebrate election results, we are reminded that nothing is as important as the lives of these fellow Arkansans, and our hearts go out to their families," Huckabee said.

At the W.J. Matthews Civic Center in Atkins, a shelter was empty except for a American Red Cross volunteers and a single touchscreen voting machine. The civic center had hosted an election precinct earlier Tuesday.

Cell phone pictures sent to television stations showed a dark, broad funnel approaching Atkins. Traffic was snarled on nearby Interstate 40, with tractor-trailers on their sides.

At least six tornadoes touched down in the 100 miles between Oxford, Miss., and Jackson, Tenn., according to the National Weather Service in Memphis, where deaths and damage were also reported.

One storm tore a large part of the north wall off Hickory Ridge Mall in Memphis. A few people north of the mall took shelter under a bridge and were washed away, but were pulled out of the Wolf River with only scrapes, said Steve Cole of the Memphis Police Department.

Later, the system damaged a dormitory at Union University in Jackson, the same city where a 2003 tornado killed 11 people and a 1999 twister killed nine. Eight students were trapped Tuesday but weren't seriously injured, school spokesman Tim Ellsworth said.

In Arkansas, the Baxter County Sheriff's Office said debris, including parts of houses, blocked U.S. Highway 62. The town of Gassville was sealed off because of the possibility of gas leaks resulting in an explosion.

The three dead at Atkins were family members who died after their home took a direct hit, Pope County Coroner Leonard Krout said.

"Neighbors and friends who were there said, 'There used to be a home there,"' Krout said.

A tornado shredded warehouses in an industrial park in Southaven, in northern Mississippi, said Desoto County Sheriff's Department Cmdr. Steve Atkinson.

"It ripped the warehouses apart. The best way to describe it is it looks like a bomb went off," Atkinson said. "A lot of fire departments are here and we're searching each warehouse to see if there was anybody in there. It's going to be a time consuming thing and we'll probably be searching into the morning."

Officials do not know what started a fire late Tuesday at the Columbia Gulf Natural Gas pumping station near Green Grove, about 40 miles from Nashville. The fire could be seen in the night sky for miles around, with flames shooting "400, 500 feet in the air," said Tennessee Emergency Management spokesman Donnie Smith.

But the storms could have damaged the station, said Tennessee Highway Patrol spokesman Mike Browning.

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