Abstract: Employee #1 and a coworker went up the 5-in-12 pitched roof on the south side of a four-unit condominium to determine how they were going to cover the intersection of that roof with the 12-in-18 pitched roof on the north side. The morning sun had already dried off the frost on the south side, but the north side of the roof was still covered with frost. From the peak, they looked down at the area that needed plywood. Employee #1 placed his left foot on the north side of the roof. And his foot slipped on the frost. He lost his balance, slid down the north roof, and fell 18 ft from the eave to the ground. He sustained multiple fractures, for which he was hospitalized. The workers had not been provided any form of fall protection.