 The Ontario Fire Marshal's Office handled the investigation of the explosions.While the cause of the explosions had not yet been determined, on August 21, 2008, Ontario's independent safety regulator for fuels, the Technical Standards and Safety Authority (TSSA), released a statement saying that, just before the explosion, a truck driver was illegally transferring propane from one truck to another.The agency also reported that, in November 2006, Sunrise Propane was warned about its lack of safety from not stopping the truck-to-truck transfers at the company's facilities, and that truck-to-truck transfers were a frequent and routine operating practice at the facility.