During rig-down, all sections of the mast had been dismantled and only the lower sections remained pinned to the sub base in a horizontal position. Three employees were working to remove the pin from the raising line yoke to remove the line. All were wearing fall protection equipment. In order to avoid damaging the pin threads, one of the employees decided to hammer the pin out. He unhooked his safety harness so he could descend through the standpipes. As he stepped on the lower standpipe, 11.5 ft. (3.5 m) from the ground, he lost his grip and fell to the ground. He suffered a concussion and fracture of the right wrist.