Philadelphia fire investigators say they've determined that a furnace triggered a blast that killed a gas company worker in January.
The Philadelphia Daily News reports that fire department officials say the Jan. 18 blast was ignited by a furnace inside a chiropractic and rehabilitation center in the city's Tacony (tah-KOH'-nee) section.
A 12-inch gas main and a water main had both ruptured nearby a short time before the explosion. Philadelphia Gas Works workers had been trying to fix the broken gas main when the explosion happened.
The blast killed 19-year-old PGW worker Mark Keeley, who had worked at the utility for about a year. Five other PGW workers were hurt.