Abstract: At approximately 1:30 p.m. on November 3, 2011, Employee #1 was working as an electrical or electronic technician for West Tower Communications. He was unspooling wire at a jobsite on the roof of a building in San Francisco, CA. He was accompanied at the site by his foreman, a coworker who was also a technician, and two occupants of the building. Employee #1 was working on a rooftop, unspooling #2 green wire. Employee #1 lost his balance while walking backward. He tripped and fell backward through a skylight 22 feet (6.7 meters) to the concrete floor. One of the building's occupants, in a later interview, reported that he was alerted by a crashing sound in the warehouse. He found Employee #1 lying on the concrete floor. One of Employee #1's coworkers on the roof yelled through the broken skylight for the occupant to call emergency medical services and have them send an ambulance. Employee #1 was taken to San Francisco General Hospital and treated for multiple fractures, contusions, and trauma. The injury was reported to the Division by the San Francisco Police Department in a timely manner, at 2:29 p.m. on November 3, 2011. The Division investigated the incident at approximately 10:00 a.m. on November 4, 2011. It went to the site and interviewed the occupant who had found Employee #1 lying on the ground.