Official Cause Determined in South Philadelphia House Explosion

The Philadelphia Fire Department has determined the cause of a devastating explosion that leveled a South Philadelphia rowhome.

Building contractor Steve Barrientos was working inside 428 Daly Street on the morning of July 29 when natural gas from a small leak sparked a blast that brought down the two-story brick rowhome and damaged neighboring structures.

Philadelphia Fire Department Executive Chief William Dell says the contractor was attempting to light a cigarette with a butane lighter when the flame ignited the gas.

Barrientos suffered second and third-degree burns to his face and upper body in the explosion and spent days at Temple University's burn unit. Seven other people suffered minor injuries -- including a teenage girl who lived next door and fell from her bedroom into into the kitchen.

Reports following the explosion had linked the blast to a cigarette, but at the time, Philadelphia Mayor Michael Nutter called those claims simply "rumors and speculation." He added that officials needed to wait and speak with Barrientos until those reports could be substantiated.

Two homes were demolished as a result of the explosion.