Abstract: At approximately 3:00 p.m. on February 12, 2002, Employee #1 was working in the crown area of Rig 80. He was attached by a boatswain's chair, harness, and carabineer to a 0.625-in.- diameter hoist line. An air tugger was being operated to lift him by the hoist line to a position above the drill pipe elevators. He was to remove a wire line clamp from a wire line cable prior to the start of drilling. The hoist line to which he was attached was run through a 0.625-in. McKissick sheave attached to the crown of a derrick. The sheave could be opened on one side to allow for the rigging of the cable through the sheave. There is a bolt which runs through the sheave that secures the cable in the sheave. When the bolt is in place and the sheave closed, the cable can not come loose from its attachment point. As Employee #1 worked in the crown, approximately 80 ft above the floor of the rig, the hoist line fell from the sheave causing him to fall to the rig floor along with the cable. Employee #1 was killed.