Abstract: An owner of a carpentry contracting firm was on the roof of a storage building under construction. The firm had two employees, but only one of them was on the site with the owner. The firm's owner was installing siding, and he had climbed onto the roof to cut a piece of Texture 111 siding to meet the roof slope. The roof was 7 meters above the ground, and a 19-kilovolt overhead power line was 9 meters above the ground directly over the owner's head. He flipped an extension cord he was using, and it contacted the power line. The owner was electrocuted. (He also fell off the roof.) It was a damp misty day, and the plywood roof sheathing was wet. Burn marks on the wood indicated that the plywood had provided a path to ground. (The injury line was not completed on the original form.)