Abstract: Employee #1, a pipelayer, was watching coworkers use a Leibehr 932 power shovel to push a trench box under insulated electric lines. The operator had extended the boom horizontally to maintain clearance below the lines, which obstructed his vision to the right. A signalman positioned in front of the power shovel yelled to the operator to track ahead. They were both watching the clearance of the trench box and the overhead wires. Employee #1 was standing to the right of the boom and also watching the wires. The power shovel had only moved approximately 2 ft forward when the right track struck Employee #1. He sustained a fractured ankle and was hospitalized.