Abstract: Employee #1, of the Tim Ply Division of Timber Products, was involved with the repair and replacement of roof support structures and the tin roof. The employee was nailing a 2 in. by 8 in. plank to the existing warped structure. He was standing on a sheet of plywood measuring approximately 34 in. by 8 ft. The plywood was laid down over the existing supports without being nailed down or otherwise secured. No form of fall protection was being used. Employee #1 stepped backward to continue nailing when the plywood sheet shifted and tipped up. Employee #1 fell approximately 17 ft to the concrete floor. While falling, the employee struck a sprinkler pipe and was flipped from the feet first position to a face down position. The piece of plywood then fell and covered the employee. CPR was administered by mill personnel until emergency help arrived and transported the employee. He died on October 21, 1991.