Abstract: On August 5, 2008, Employee # 1, a mechanic, was working in a yard, containing various types of construction equipment, located across the street from the employer's office. Employee #1 normally serviced equipment such as asphalt paving machines, tractors, skip loaders, and water tanks for his employer, a construction contractor involved in asphalt paving of city streets and parking lots, as well as small grading and concrete work. Employee #1's supervisor, the president of the company, was away, but Employee # 1 could take direction from the office manager and the shop assistant. The shop assistant asked Employee #1 to service/repair a 48-foot by 10-foot-trailer with a cab. Employee #1 was to weld a bracket for the shock absorber, which was located under the trailer bed, approximately at the center of the bed. The horizontal height of the trailer bed was 35 inches, presumably meaning that the trailer bed was 35 inches high. The trailer bed could be lifted mechanically at the cab end, thus lowering the free end of the trailer to the ground. Employee #1 placed two mechanical jacks to support the two free ends of the trailer bed. As the bed was in an inclined position, elevated at the cab end, Employee #1 placed a hydraulic jack underneath the middle part of the bed, next to the location where the bracket work was going to be done. Just before starting the bracket work, Employee #1 decided to raise the hydraulic jack by maneuvering it. As he was operating the hydraulic jack, the jacks got displaced from their respective positions, causing the trailer bed to drop. The trailer bed fell on Employee #1's back, as he was on his knees and facing the floor to do the repair work. Employee #1, who was seriously injured, dragged his body out from underneath the bed and called for assistance by cell phone. Employee #1 sustained a fracture to his left femur, in addition to fractures and/or pain to his shoulder and ribs. Employee #1 was hospitalized at Long Beach Memorial Medical Center from August 5, 2008 through August 11, 2008. The investigator determined that the cause of the accident was failure to secure the mechanical and hydraulic jacks.