BELLEFONTAINE, Ohio -- No determination yet as to a cause for the explosion last week at the one-time doctor's office in Bellefontaine.

All causes could not be ruled out, but investigators for the State Fire Marshall's office suspect a propane leak was ignited by utility equipment in the basement.

There were no injuries in the blast last Wednesday. It destroyed a former single-family home used as the office of Dr. Matthew Hasford, a urologist. The office was no longer in business.

Debris was found a half-mile away and neighboring buildings were damaged. The explosion also caused a van parked nearby to roll over onto its side.