Abstract: A crane supporting a diesel-powered pile driver was located on a floating barge. Employee #1 and a coworker removed a used cushion block from the hammer helmet. A new laminated 24 in. square by 12 in. thick plywood block was pressed into the helmet and bridge spikes driven into it. The hammer was then raised approximately 50 ft into the leads in preparation to lift a second pile driver on top of the first pile. The employees were standing on the drop leads, preparing to remove a protective aluminum block from the splice plate, when the bottom 4 1/2 in. of the new cushion block delaminated below the bridge spikes. The piece fell, bounced off the lead webs, and struck Employee #1 on the head. He died that afternoon.