Abstract: At approximately 2:15 p.m. on September 17, 1992, Employee #1 was adding a section of bore pipe to an existing bore pipe. The boring machine was turning the bore pipe to thread it onto the pipe in the ground. Employee #1 was guiding the turning bore pipe. He was wearing a traffic vest, which became wrapped around the rotating bore pipe. He tried to hold the vest from his body, but in doing so, his left thumb was caught between the vest and the pipe. He pulled back his left arm, causing his thumb to be amputated. Employee #1 was taken to Memorial Hospital, in Bakersfield, CA, and then transferred to UC Irvine for reattachment surgery.