Abstract: At approximately 9:30 a.m. on July 6, 1999, Employee #1, a company foreman, was installing chimney flashing on the second story of a home. He walked over to the roof valley, placed both hands on the upper roof, and jumped down 4 ft to the lower roof, landing between two rafters on the weakest area of the its chipboard sheeting. The sheeting broke and he fell 15 ft through the lower roof onto the concrete slab floor. Employee #1 sustained a fractured wrist and two compressed vertebrae, for which he was hospitalized. The cause of the accident was Employee #1's misjudgment of the hazard posed by the roof sheeting.