Abstract: Employee #1 was standing on the fourth rung of a 12 ft fixed vertical ladder, about 8 ft above a stair landing. He had just finished removing some tools from the roof by lowering them with a rope through a roof hatch. To close the hatch, Employee #1 reached over his head to grab the hatch handle with one hand, while holding onto the hatch sill with the other. Because of the way the hatch was configured, he had to let go of the sill for the hatch cover to close. Employee #1 either slipped or lost his grip and fell backward off the ladder. He struck a 42 in. tall handrail on the landing and then fell 22 ft 6 in. down the stairwell to the bottom floor, for a total distance of 30 ft 6 in. Employee #1 suffered cuts to his head and multiple bruises. His coworker had already left the work site when the accident occurred.