A barrage of thunderstorms that spawned apparent tornadoes (search) caught people by surprise as it peeled roofs off buildings, damaged homes and flipped trucks across much of central Indiana.
Officials said at least five people suffered minor injuries as a result of the storms Tuesday. No deaths or serious injuries were reported.
The same weather system that spawned the Indiana storms apparently fueled storms that killed four people in northern Illinois.
"It would appear that from all that we know now, that this could have been much worse," Indiana Gov. Joe Kernan (search) said.
Kernan planned to travel to Jamestown, a hard-hit town about 20 miles northwest of Indianapolis, to assess the damage Wednesday.
Authorities said from three to six people suffered minor injuries in Jamestown, and about a dozen homes were damaged by the storm. Officials declared an emergency overnight and set up a command post in the town's fire station.
Alden Taylor, a spokesman for the State Emergency Management Agency, said one person was injured when a tractor-trailer was blown off Interstate 74 in Boone County. He did not know how badly the person was injured. The storm blew as many as four semitrailers off the highway.
A Kokomo woman was treated for minor injuries after she was hit by debris, said St. Joseph Hospital spokeswoman Nancy Madru.
More than 30 teenagers were attending a party in the Kokomo Skating Arena when witnesses said a tornado tore the building's roof off about 6:30 p.m. No injuries were reported.
Employees at the rink saw the funnel cloud approaching and warned those inside to get out of the center of the floor and take cover along the building's walls.
"You know the rides they have at amusement parks, where the roof raises and then drops like it's going to hit you? That's what it was like," said Jill Foster, sponsor of one of a Tri-Central High School group attending the event.
Taylor said the storms popped up without warning.
"It was a surprise to about everybody," he said. "It was warm, but those are what are called popcorn storms that will suddenly appear. It's very difficult to predict them."
The storms left a trail of damage across several communities north of Indianapolis and cut power to thousands of customers.
PSI Cinergy spokeswoman Angela Protegere said more than 2,400 of its customers statewide lost electricity because of storm winds, including about 1,600 in Kokomo. She said power had been restored to all but a handful of homes and business by Wednesday morning.
Mike Shartran, a spokesman for the National Weather Service (search), said the agency planned to assess the storm damage Wednesday and did not immediately know how much of the storm damage was caused by tornadoes.