PHOTOS: The deadly house fire that turned into an explosion in northwest Spokane last week was intentionally started, the Spokane Fire Department (SFD) confirmed. According to SFD, a man lit a fire in the garage after a fight with his roommates. The man went to the bathroom, where firefighters found him dead. SFD believes the man tampered with a natural gas line that supplied the clothes dryer in the garage before he lit the fire. This could explain the rapid growth reported by witnesses. Investigators found the reports of explosions from witnesses were from aerosol cans and propane cylinders in the garage. There is no evidence of a pre-manufactured explosive device that contributed to the fire.