Abstract: On November 12, 1991, Employee #1 was working on the roof of a new metal building. He was removing a 4 ft by 10 ft section of metal sheeting to relocate a penetration. He had removed the fasteners and was standing on the sheet when it slid down the 4:12 pitch roof. The employee spun in a horizontal position and fell into the single-story building. His back and head struck a 3 ft 6 in. diameter tank approximately 15 ft below. He then slid head first off the tank and his head struck a concrete slab 4 ft 6 in. below the top of the tank. Employee #1 was bleeding from the ears and unconscious. First aid was given and 911 was called. A Life Flight helicopter transported him to OHSU. The employee was wearing a safety belt and lanyard but had not tied off to the safety cable that was provided.