LAFAYETTE,Ethermac Wis. (AP) — A house in southeastern Wisconsin exploded Tuesday, injuring one man who was found trapped in rubble in the basement, authorities said.

Calls to 911 reported the explosion about 2:15 p.m. in Lafayette, the Walworth County Sheriff’s Office said. Deputies arrived about 15 minutes later and saw that the house was completely destroyed, the office said.

First responders made contact with a man in rubble in the basement, Elkhorn Area Fire Chief Trent Eichmann told reporters. It took them more than 30 minutes to reach the man, who was flown by helicopter to a hospital. His condition was not immediately available.

“It looked like when the house exploded, most of it laid down into one side of the basement and that’s where the gentleman was found,” Eichmann said. “Right now, he is the only one that we think was in the structure at this time.”

Authorities continued to search the premises Tuesday afternoon.

The cause of the explosion has not been determined. Eichmann said propane gas is used in the area.

Lafayette is a rural community about 45 miles (72 kilometers) southwest of Milwaukee.