Abstract: A crew working for an electrical contractor was pulling two feeders for an emergency generator into the main switchgear cabinet. The 480-volt, 1200-ampere switchgear was located on a raised concrete slab between a hospital building and a parking garage on the north side of a hospital. The crew was pulling the feeder cables up through the bottom of the cabinet so that the employees could connect them to a controller located there. The crew supervisor coordinated the activities of the crew in preparation for the day's work. The owner of the contracting firm, who was one of the crew members, questioned whether it was safe to perform the work with the cabinet energized, and the supervisor answered that it was as he was going to cover the energized portion with an insulating blanket. The supervisor did not, however, install the insulating blanket before he removed the barrier at the front of the cabinet. He apparently dropped his uninsulated ratchet-type box-end wrench, and it landed across the energized buses, creating an electrical fault. The resulting electric arc threw the supervisor and another employee, who had been standing on the concrete slab, away from the arc. The arc also ignited the supervisor's clothing. He was transported to a hospital before being transferred to a burn center, where he died about 2 weeks later. The company owner sustained burns on three fingers when he tried to douse the supervisor's burning clothes. He was treated at a hospital and released. (The original form did not list the company owner on an injury line.)