The Vancouver Fire Marshal’s Office was unable to determine the cause of a Friday afternoon RV fire in east Vancouver.Vancouver fire crews responded around 3:30 p.m. to the 15300 block of Southeast Stevenson Drive. Crews found a motor home engulfed in flames, according to emergency radio traffic monitored at The Columbian.The fire was extinguished in a few minutes, according to Dean Bray, lead deputy fire marshal. The owner of the 1995 RV — almost completely destroyed from smoke, water and fire — was not inside at the time, Bray said. The Red Cross assisted the man in finding living arrangements. While several accidental causes, including an electrical failure, are possible, the fire marshal’s office could not pinpoint one, Bray said. No surrounding structures, save some soot that carried into a nearby shed, were affected.