Abstract: At approximately 10:55 a.m. on June 28, 1987, Employees #1 and #2 were doing the semi-annual maintenance of washing the sawdust off the barrel type roof at the plywood mill where both employees were employed. Employee #1, who was using a fire hose to do the washing, was wearing a safety belt and lifeline. Employee #2 was tending the line. Employee #1 slipped and slid down the roof. Employee #2 was also pulled down and both workers went over the roof edge and fell 24 feet to the asphalt pavement. Employee #1 suffered a fatal head injury and Employee #2 a crushed left heel and two fractured vertebrae. The key factor was that neither worker was tied off. The pitch of the barrel type roof got steeper near the edge and the smooth surface of the roofing membrane became very slick when wet.