Abstract: Employee #1, a campground manager, worked for a resort operator on Catalina Island. On the day of the accident, he was at the Hermit Gulch Campground, attempting to light a 100 gallon propane A.O. Smith water heater, model FGR 100 231, serial #ML94-0079063-S-06. The main propane tank for the water heater had just been replaced, and the hot water for the upper showers was turned off. The propane water heater was located in an enclosed, approximately 4 ft wide by 15 ft long area of the building that housed the showers. Employee #1 bled the propane line while lying down on a foam camping mat inside the water heater room. He then went to empty the trash cans around the campground so that the propane could disperse in the air. After about 15 minutes, Employee #1 attempted to light the pilot again while lying on the foam mat. He had the pilot lit, and was pulling out the sparker when a ball of fire erupted. Employee #1 sustained second-degree burns to his hands. He failed to test the air to determine if the concentration of the flammable vapors exceeded 25% of the lower explosive limit prior to introducing a source of ignition.