Abstract: On June 9, 2003, Employee #1 was with a ground crew conducting concrete pile stabbing operations. After the crane anti-two block weight came loose from a switch at the point of the boom, the weight slid down the cable and landed on the headache ball. The superintendent and crew then wired the switch back to the point of the boom. The superintendent instructed the ground crew to hook up to the next pile while the boom was raised. When the crane operator began to remove slack from the cables, the leveling block fell and struck Employee #1 on his head, killing him. The investigation revealed that one of two 0.125-in. cables that originally suspended the anti-two block weight from the switch had wrapped around the headache ball and apparently come through the safety latch on the hook. The cable then became lodged in the "Y" part of the choker that held the leveling block on the hook. As the crane operator began to remove the slack from the cable, the headache ball began to spin, causing the cable to tighten. As the ball continued to spin, the cable continued to shorten, first forcing the safety latch on the ball hook back, and then slightly turning the hook. As a result, the choker slid out from the hook and fell to the ground.