Abstract: On October 17, 2003, Employee #1, a carpenter, was on a roof, welding metal clips along the outer edge of a four-story building. He was holding onto a wire rope guard rail with his left hand when a coworker, a welder who worked for a subcontractor, hung an electrode holder from his welding machine on the guard rail. The rope guard became energized with 27 volts and 170 amps. Employee #1 received an electric shock, which caused him to step backward into a 2 ft long by 2 ft wide by 4 in. deep hole. His foot became caught between horizontal rebar and a concrete wall, and he fell backward on the concrete roof. He sustained a fractured tibia and fibula, and a dislocated ankle. The hole was uncovered, and the general contractor and subcontractor did not recognize the danger that the hole and the rebar presented. The inner compression spring in the electrode holder was not insulated. Employee #1 was wearing cut-resistant work gloves with no fingers, allowing his bare fingers to contact the energized wire rope.