An explosion and fire occurred in a silane gas room in a silicon thin-film photovoltaic module fabrication plant, resulting in one fatality, and completely destroyed the gas room. The fire also spread outside the room through a polypropylene (PP) exhaust duct to the cleanroom and exhaust scrubbers, resulting in significant damage to the plant. This article investigates the incidents leading up to the explosion, fire escalation, and the incident response. This accident stressed that PP ducts must not be used to transport flammable or nonflammable gases. Because the cylinder change process was also identified as a problem, an appropriate procedure is described. Lessons learned in the plant management, operation, and engineering design are discussed in detail. (c) 2006 American Institute of Chemical Engineers