Abstract: Three employees were welding the rain gutter on a weapons elevator located on the flight deck of the U.S.S. Coral Sea, an aircraft carrier. They were using the elevator car as a work platform. Two electricians were using continuity testers on the weapons elevator electrical system. The main circuit breaker for the weapons elevator had been tagged "Caution." It was only to be operated by the electrical department. On June 24, 1984, the electricians checked the circuit breaker at 10:30 a.m. It was still open and tagged. When the electricians activated a switch in the electrical system the elevator car moved up approximately 6 feet to the flight deck. This action struck one employee on the shoulder and crushed another's head between the elevator car and flight deck. Subsequent investigation revealed that someone had switched on the main circuit breaker, which still had the caution tag on it.