Clark died as Story and his wife tried to navigate debris-strewn roads in their pickup truck, they said.
"He never had a chance," Story's wife, Nova, said. "I looked him right in the eye and he died right there in front of me."
President Bush said he called the governors of Alabama, Arkansas, Kentucky, Mississippi and Tennessee and assured them the administration was ready to help and to deal with any emergency requests.
"Loss of life, loss of property—prayers can help and so can the government," Bush said. "I do want the people in those states to know the American people are standing with them."
The system moved eastward to Alabama Wednesday, bringing heavy rain and gusty wind, causing several injuries in counties northwest of Birmingham.
Weather service experts also investigated damage in Indiana to see if it was caused by tornadoes.
An apparent tornado damaged eight homes in Walker County, Alabama, and a pregnant woman suffered a broken arm when a trailer home was tossed by the wind, said county emergency management director Johnny Burnette.
"I was there before daylight and it looked like a war zone," he said.
Fire, Wind, Water
Northeast of Nashville, a spectacular fire erupted at a natural gas pumping station. The station took a direct hit from the storm, but no deaths connected to the fire were reported.
About 200 yards (180 meters) from the edge of the plant, Bonnie and Frank Brawner picked through the rubble of their home for photographs and other personal items. The storm sheared off the second story of the home.
"We had a beautiful neighborhood, now it's hell," said Bonnie Brawner, 80.
More than 20 students were stuck behind wreckage and jammed doors, mostly for short periods, in battered dormitories at Union University in Jackson, Tennessee. Tornadoes had hit the campus in the past, and students knew the drill when they heard sirens, said Union University President David S. Dockery.
"When the sirens went off the entire process went into place quickly," Dockery said. Students "were ushered into rooms, into the bathrooms, interior spaces."
He said about 50 students were taken to a hospital and nine stayed through the night. But all would be fine, he said. The students "demonstrated who they are and I'm so proud of them."
In Memphis high wind collapsed the roof of a Sears store at a mall. Debris that included bricks and air conditioning units was scattered on the parking lot, where about two dozen vehicles were damaged.
A few people north of the mall took shelter under a bridge and were washed away in the Wolf River, but they were pulled out with only scrapes, said Steve Cole of the Memphis Police Department.
Worst in a Decade
Winter tornadoes are not uncommon. The peak tornado season is late winter through midsummer, but the storms can happen at any time of the year with the right conditions.
The death toll of 50 ranks among the top 15 from tornado outbreaks since 1950, said Greg Carbin, the warning coordination meteorologist at the center in Norman, Oklahoma, just south of Oklahoma City.
The tornadoes could be due to La Niña, the cooling of the tropical Pacific Ocean that can cause changes in weather patterns around the world. It is the opposite of the better-known El Niño, a periodic warming of the same region.
Recent studies have found an increase in tornadoes in parts of the southern U.S. during the winter during La Niña. On January 8, tornadoes were reported in Arkansas, Illinois, Missouri, Oklahoma and Wisconsin. Two died in the Missouri storms.
In this round of storms, there were 67 eyewitness accounts of tornadoes but the number of twisters likely won't be that high because some probably saw the same funnel cloud, said Carbin. He said a reasonable guess is that 30 to 40 tornadoes touched down.
Most communities had ample warning that the storms were coming—forecasts had warned for days severe weather was possible. But in at least one rural community, there was no siren to alert residents the severe weather had arrived.
In Kentucky's Allen County, officials had requested funding for a siren at the fire station but don't yet have one. Even if they did, officials wondered if it would have helped.
"It came in quick," Judge-Executive Bobby Young said. "Probably, warning devices wouldn't have helped any."
Contributing to this report were Associated Press writers Ryan Lenz in Greenville, Kentucky; Jon Gambrell in Atkins, Arkansas; Holbrook Mohr in Jackson, Mississippi; Seth Borenstein in Washington; Murray Evans in Oklahoma City; and Woody Baird in Memphis, Tennessee.
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