Abstract: A power line worker and a ground worker were removing an electrical service. Working on a utility pole, the power line worker removed a crossarm and rested it on his positioning strap. The ground worker let a hand line down to the line worker who was to attach it to the crossarm so that the arm could be lowered to the ground. (The crossarm was not attached before being removed because of the danger of contact with an energized conductor above and because of the possibility that the arm could swing and knock the line worker off the pole.) The power line worker's left foot slipped, and he dropped the crossarm as he tried to reset his climbing gaff. As it fell, the crossarm hit a telephone service guard arm on the pole and catapulted horizontally. The crossarm fell onto the ground worker, who was wearing a hard hat and who was about 15 feet from the pole at the time. The arm struck the employee on his head, neck, and shoulder. He was hospitalized for his injuries, which included a concussion, a broken shoulder, and lacerations to his neck.