Abstract: At 11:26 a.m. on February 12, 2006, Employee #1 and a coworker, both utility workers, were removing a 1,200 lb. slide gate valve from a bottom of a steel ladle for maintenance and inspection. In order to remove the valve, a one ton capacity jib crane is used. However, the boom of the jib crane, when extended, is directly in the path of a 240 ton capacity overhead crane. To prevent the overhead crane and the jib boom from striking each other, the employer had a procedure in place that required the jib operator to contact the overhead crane operator through radio before extending the boom. As a secondary precaution, the employer also required warning lights to be used. As Employee #1 was near the gate valve, assisting the jib crane remove the gate, the overhead crane struck the jib's extended boom. The load of the overhead crane then swung and struck Employee #1. Employee #1 was hospitalized and treated for severe fractures. The accident investigation revealed that the crane operator received no radio message and, although the warning lights were operational, they could not be seen by the overhead crane operator due to restricted visibility on one side of the crane's cab. Employee #1 was wearing proper personal protective equipment to include a hardhat, safety glasses, and metatarsal covers.