Abstract: At approximately 3:00 p.m. on January 10, 2004, Employee #1 and coworkers were lowering the mast for the relocation of a rig. Two of his coworkers, a derrickman and a motorman, ascended the derrick to remove the beeper pins and descended to the rig floor. For some reason, while located on a ladder near the floor of the rig, Employee #1 released himself from the anti-fall line. The upper section of the mast released and descended uncontrollably, only stopping after becoming wedged in the rig floor a couple of feet. This caused the rig to vibrate and employee fell off the ladder. He proceeded to fall over the guardrail and about 20 feet to the choke manifold. Employee #1 was hospitalized at Kern Medical Center and treated for a broken femur.