Abstract: At approximately 3:00 p.m. on January 18, 2006, Employee #1, a floor man with Key Energy Services, Inc., was using a mechanical winch to pull pump rods during servicing of an oil well. He would then transfer the rods to a rack located on the service rig derrick. While transferring the fourth pump rod set to the rack, a sheave came loose from the rod transfer pneumatic cylinder and fell approximately 80 ft to the well head area, breaking through Employee #1's hard hat and striking his head. He was hospitalized at Mercy Hospital for treatment of unspecified fractures. The investigation concluded that the equipment involved in the accident had been serviced and inspected prior to the accident as required. The employer had the required safety programs implemented, including employee training and hard hat usage. The employer could not have foreseen that the sheave involved in this accident would fall from the derrick.