Abstract: At approximately 9:15 a.m. on July 19, 2004, Employee #1, an electrician's helper, was helping to rewire an old high-rise office building in Los Angeles, CA. He applied fire stop to the electrical conduits in the walls on the first floor. The conduits brought wires up from the basement, where high-voltage power lines entered the building, and reduced the voltage to 120/240 volts. Employee #1 then remembered a 1 1/2 in. conduit inside one of the service cabinets, which was on the ground floor. The conduit needed a strap installed before more power lines could be brought up from the basement. Employee #1 removed two corner screws in the cabinet's door so he could open it and he was leaning forward over the splash apron to access the conduit when his head contacted a 120-volt busbar. He received an electric shock and was rendered unconscious. A coworker started CPR and revived him. Employee #1 sustained small burns on the bottom of his right arm and left thumb, which provided paths for the electricity, and a severe burn on the right front part of his skull. All the service cabinets on the first floor were de-energized except for one that was backfed to supply 120 volts for lighting the building. The cabinet Employee #1 opened had a lockout on the breaker that was accessible from outside the cabinet, However, when he removed the corner screws, the lock stayed on the breaker as the door opened. The busbars inside the cabinet were also backfed and, had the breaker been closed, an explosion would have occurred in the basement.