Abstract: On September 13, 2003, Employee #1, was alone on the sixth floor of a concrete warehouse in Los Angeles, CA, that was being converted to apartments. Steel reinforced shear walls were being put up to replace poured-in-place concrete. Employee #1 was standing on a 61 ft concrete balcony and was using a rope to hoist up a 20 ft long piece of rebar. The rebar had reached the balcony when, in tipping it, the rebar contacted a 34,500 volt electrical conductor that was 9 ft away and approximately even with the floor. At the same time, Employee #1 touched the building's concrete wall, which allowed the electrical charge to go to ground through the subsurface rebar in the concrete. This resulted in an arc blast. Employee #1 sustained first- and third-degree burns over 30 percent of his body, for which he was hospitalized. The balcony had steel guardrails, but the conductor, which was apparently made of twisted aluminum wires, was not insulated. At the time of the accident, the closest supervisor was on the fifth floor.