Abstract: At approximately 9:15 a.m. on July 17, 2009, Employee #1 and coworkers were removing the top four layers of a sheet metal roof to perform repair work on the roof. The building was an empty storage facility attached to a corrugated box manufacturer. The roof was approximately 80 feet by 320 feet, and the employees had completed approximately half of the roof. At the time of the accident, the employees were working in an area that was approximately 100 feet by 20 feet. They had removed the top three layers of the roof and only the lightweight concrete and sheet metal remained. At this point, the crew foreman felt the area flex slightly when he walked on it and determined the area to be unsafe for the employees to work. He instructed one of the employees to become the safety monitor and he erected a warning flag line approximately 6 feet from the edge of the entire building. The foreman instructed two of the employees to attach their harness to the safety cart for fall protection. These two employees were working in the area where the foreman had determined the roof to be unsafe. The two employees were then instructed to remove the layer of lightweight concrete in an area that was approximately 20 feet by 15 feet. The removal of the lightweight concrete exposed the bare sheet metal. Employee #1 and a coworker began removing 2-inch by 6-inch pieces of wood from the edge of the building. After removing several pieces of wood, Employee #1 was bending down to remove another piece and fell through the roof. He fell approximately 25 feet to the floor of the building and was killed.