Tennessee was hardest hit, with tornadoes striking five counties and killing 19 people along one 25-mile path Sunday, the National Weather Service said. The Highway Patrol sent teams to the area Monday with search dogs.

Betty Sisk said she and her 13-year-old daughter and 10-year-old son took cover in a closet until the twister blew their house apart and threw them into the yard.

"By the time the (tornado) sirens started going off, it was at our back door," Sisk said Monday. "I didn't hear a train sound, I heard a roaring."

Nothing remained of Sisk's wood-frame home Monday but the concrete steps. A nearby house was destroyed, and Sisk said she had been told the elderly couple who lived there were dead. Another neighbour's home was blown about 30 feet off its foundation.

Severe thunderstorms, many producing tornadoes, also struck parts of Iowa, Kentucky, Arkansas, Missouri, Ohio, Illinois and Indiana. Strong wind was blamed or at least three deaths in Missouri. A clothing store collapsed in southern Illinois, killing one man.

The weather service's Storm Prediction Centre in Norman, Oklahoma, said it had preliminary reports of 63 tornadoes.

Most of the Tennessee deaths were reported around the Gibson County towns of Bradford and Dyer, said James Brown, assistant emergency management director for the county. Among the dead were a family of four from Bradford, officials said.

Tennessee officials estimated 1,200 buildings were damaged in Gibson County alone.