Abstract: At approximately 11:50 a.m. on June 12, 2009, an employee and the employers' crew were working on metal decking and were preparing to lay sheathing onto metal decking for the roof substrate. According to the crew foreman, and two other coworkers, the employee had lifted a section of 4-ft by 8-ft plywood covering a skylight which exposed the opening below. The other crew members were at the skylight location staging plywood, materials and tools required for the work. No one at the location witnessed what precipitated the actual fall. The foreman said that he turned around and glimpsed the head and shoulders of the employee already falling through the opening. The employee fell approximately 14 ft. onto the concrete floor below and suffered a skull fracture, dislocated shoulder, fractured vertebrae and ribs. The employee was admitted to Stanford Hospital for treatment of his injuries. The employee suffered a head injury and did not recall what caused him to fall. 2. The employee and the other workers on the crew each had harnesses but were not using them for fall protection at the time the skylight covering was removed.