Bellefontaine, OH- Investigators believe that the cause of an explosion at a doctor’s office building in Lake Township on July 3 was a propane leak, the State Fire Marshal said today.

The investigators believe that utility equipment in the basement ignited the explosion, but the case is still undetermined because they could not rule out all possible causes.

The explosion at about 10:30 p.m. Thursday destroyed a house that had been converted into a doctor’s office on Rt. 68, shattering- windows of nearby homes, businesses and vehicles. The doctor’s office had been closed, so the building was vacant at the time of the explosion. Nobody was injured.

Debris from the blast was found up to a half mile away from the building, causing damage to neighboring structures and rolled a nearby van onto its side.