ROSS TOWNSHIP, Pa. -- A suburban Pittsburgh man whose home caught on fire and partially collapsed slept through the entire ordeal.

Edward Stefanick, 49, was awakened by firefighters doing a walk-through of the Buckhill Road home more than two hours later.

Ross Township Fire Marshal John Reubi said he was "flabbergasted" that anyone survived the blaze, which broke out at about 2:40 a.m. Sunday and was reported by a passer-by.

Firefighters were initially unable to search for victims because part of the roof collapsed. After controlling the fire, firefighters walked through more than two hours later and found the man in a bedroom. Reubi said it appeared the man had no idea what was going on.

Officials said the house had several additions, perhaps shielding the man's room from flames. He was treated for smoke inhalation at UPMC Mercy, where he is expected to recover.

Stefanick told his rescuers that he had no explanation other than he was in a deep sleep.

The cause of the fire is under investigation.