Abstract: At approximately 9:35 a.m. on October 6, 2006, an employee working for Power Air Conditioning Company was installing HVAC units and associated ducting on the roof of a building at a job site located in Los Angeles, California. He was working on an HVAC pad that was located 45 in. from an existing skylight. He lost his balance by tripping on a pail of screws and fell through the skylight, approximately 35 ft to a concrete floor. He suffered multiple fractures of both legs and severe head trauma. A coworker telephoned emergency medical services, and the LA City Fire Department responded. The employee was transported to Harbor UCLA Medical Center, where he was hospitalized.