Abstract: A six-member power line crew was performing an emergency repair of an overhead power line at a remote location. Before work started, the supervisor held a training session, and the employees went over the best procedure to use for the repair. The power line was running in a north and south direction, with a utility pole on each side of a dry creek. The banks of the creek were extremely steep with a slope of about 60 degrees, and the terrain was loose, broken shale. The crew decided to use a throwing ball to start carrying successively larger diameter pulling line across the gap. One of the crewmembers, who had the throwing ball, walked down the slope. The shale gave way beneath his feet, and he slid approximately 90 meters to the bottom of the hill, breaking his ankle. He fell feet first and used his hands on the slope to slow his fall. A California Department of Forestry helicopter transported the injured worker to a medical center. He was transferred to a hospital for ankle surgery and was hospitalized for 5 days. Thick brush on the hillside had made it difficult for the employee to assess the security of his footing.