Abstract: Employee #1 was taking down concrete roof support panels during the demolition of a building. The building skeleton consisted of steel I-beams with fiber-like board sheeting on the exterior. The building's center portion was hollow (no floors between the roof and the ground). While standing in the middle of another panel, Employee #1 slipped a sling around a concrete panel that a crane was to lift. The panel that he was standing on broke, and Employee #1 fell approximately 40 feet through the roof level to the wood floor. Approximately half way down, he struck a steel beam. Employee #1 sustained bruises on his back and a fractured bone in his back. The employees were not wearing fall protection or using any other kind of fall protection. Employee #1 had received basic training covering proper clothing and instruction on job-related operations of demolition.