Strong storms rumbled across parts of western Iowa early Tuesday blowing off roofs and toppling branches and power lines.
Powerful storms pushed through Auburn, in Sac County about 1:30 a.m., blowing off roofs and causing some structural damage to buildings, including foundations that shifted, said Brenda Brock, meteorologist-in-charge at the National Weather Service in Des Moines.
"I don't know the what the conclusion will be as far as the cause of the damage, but it will probably be strong thunderstorm winds," she said.
There was no confirmation of a tornado in the area, Brock said.
Most of the damage in the town of about 300 people was in the downtown area, where several older, red brick buildings were damaged.
The city's maintenance shed was especially hard hit. The building's roof collapsed and two walls caved in.
"Must have been a tornado," said Leonard Hamilton, a view shared by many onlookers who gathered just after dawn to survey the damage.
"The way some of these trees got twisted, you wouldn't figure a straight-line wind would do that," he said. "It must have been a tornado."
Authorities also were assessing damage in Correctionville, in Woodbury County, where Tuesday's storm caused roof damage and knocked down trees and power lines.
Gary Brown, the county's emergency management director, said there was also was quarter-size hail reported in the Lawton and Bronson areas.