Abstract: Employee #1, the 20-year-old foreman of a crew installing traffic control signs along a secondary road, was using a National Crane Company truck-mounted crane, model 800B, to pour concrete for the base of a highway sign. A large funnel or chute had been set up to transport and deposit the concrete. Two coworkers had inserted a wooden plug in the bottom of the chute so that it could be filled with concrete. When the chute was full, the crane lifted it into position and the crew used a hammer to knock out the plug. When the plug was free and the concrete was flowing, one of the coworkers then manually guided the chute. At the time of the accident, the coworker felt the chute begin to drop and he yelled to the other coworker to run. When they were clear, they found that the boom had broken free, catching Employee #1's head against the safety rails of the crane operator's station. He died of crushing injuries. The boom had come loose because the pedestal mounting bolts had failed.