An employee was working inside an 8' x 26' steel trench box and was helping an excavator operator install a 30" ductile iron pipe. He directed the track excavator operator to place a bucket of stone bedding for the next pipe to be installed. The excavator operator dumped the bucket of stone into the trench and began to level the stone. The employee was then caught between the excavator bucket and the bell of the pipe, suffering a fractured left leg, fractured ribs, a fractured pelvis, and punctured lungs. He was hospitalized and had surgery.