Someone ransacked and vandalized a piece of dredging equipment floating in the Kansas River, sheriff’s officials said this week.

The dredge, which belongs to Penny’s Concrete Inc., was being used to take sand from the river for concrete mix. An employee found it damaged about 6 a.m. Friday off the south bank of the river just north of the 800 block of East Eighth Street, said Lt. Kathy Tate, a Douglas County Sheriff’s spokeswoman.

Someone apparently knocked over trees from the river bank and used them to climb onto the dredge, Tate said. The suspect tampered with electrical switches, went through tool boxes, stuck screwdrivers into the floor, and stole two fire extinguishers and a cell phone.

The suspect then set fire to the trees used to climb onto the dredge, Tate said. The dredge contained large amounts of fuel, she said, but the fire apparently didn’t spread to it.

No damage estimate was available Wednesday.

Dredging on the river has been a controversial issue in recent years. Environmentalists want the practice to stop because they say it destabilizes structures such as bridges and dams, blocks access to canoers and stirs up sediment contaminated with insecticide.

But no one has claimed responsibility for the crime, and police say it could have been a random act of vandalism.

“Right now, it’s pretty wide open,” Tate said.

The concrete company’s owner, Bill Penny, of Lawrence, said he had no idea who did it and didn’t have any reason to suspect environmentalists.

“There are so many educated people that are on that side of the issue that I would never even want to think that was a possibility,” Penny said.

Charles Benjamin, a local attorney who represents the Kansas chapter of the Sierra Club, said he hadn’t heard anything about the incident until notified by a reporter.

“We believe that the dredging is causing substantial damage to the river… but we do not support vandalism or any other kind of acts of property damage,” he said.