Abstract: At 8:00 a.m. on September 12, 2006, Employee #1 was working as a full-time employee for a metal products fabricator as a maintenance mechanic. His main duty was to maintain and service equipment. Employee #1 had been a maintenance mechanic for several years with the employer and was often the one who serviced the equipment on the roof. On the day of the accident, he was on the roof of the plant to service fan motors. There were acid tanks in the plant in which the wire products were dipped for finishing. The acid vapors evaporated into the air from the tanks and caused the roofing sheet metal to deteriorate. The roof was single layer; that is, the ceiling in the building was the actual roof on the exterior of the building. While Employee #1 was on a deteriorated portion of the roof, it gave way, and he fell approximately 40 feet. Since then, Employee #1 has been comatose at the Los Angeles County+USC Medical Center Hospital. He also has unspecified fractures and a head injury.