Abstract: On May 8, 2006, Employee #1 was working as a maintenance supervisor in the construction of a concrete plant. He was overseeing and assisting in the setting of a steel column on top of a concrete pier 12 feet above grade. Working from a catwalk, he had tightened bolts on one side of the column, while a coworker, working from a ladder, tightened bolts on the other side of the column. The maintenance supervisor crawled over the guardrail of the catwalk onto the top of the pier and helped the employee on the ladder tighten the bolts. When they were finished, the maintenance supervisor was crawling back over the guardrail onto the catwalk, when he slipped and fell, striking his head on the concrete surface 12 feet below. He sustained a concussion, and he was killed.