Abstract: Workers were removing a 75.7-kiloliter gasoline tank and a smaller 45.4-kiloliter fuel storage tank. Before excavation began, the workers drained the storage tanks, but a few centimeters of fuel still remained at the bottom of the storage tank. Two days earlier, one of the employees was excavating around the storage tank when he struck the storage tank with the excavator bucket and punctured a hole in the tank. The hole allowed pea gravel surrounding the tank to enter. On the day of the accident, the same employee entered the unprotected excavation and was working at a depth of approximately 3.4 meters. He used a shovel to remove the pea gravel from the storage tank through the hole. He then began patching the hole with a scrap of fiberglass, attaching it to the outside of the tank using a Black and Decker 18-volt, battery-powered, cordless drill to drive 51-millimeter-long self tapping screws. He had not tested the tank for the presence of flammable vapors. While he was driving the second screw, the storage tank exploded, engulfing the employee in flames. He was burned over 60 percent of his body and receiving second- and third-degree burns to his arms, back, chest, legs, and face. He was hospitalized for his injuries for approximately 3 weeks.