Abstract: Iron workers were emplacing hydraulic jacks in preparation for lifting a portion of a bridge the following day. The bottom couplings of each were connected to a manifold system that was connected to a pump. The foreman wanted to place enough pressure on the jacks to prevent theft. Once the system was pressurized, the ram in one of the jacks started to move; the other showed no sign of movement. Once the first ram was in place, the valve to the jack was closed. The ram on the second jack started to move, then shortly thereafter, a loud report was heard. The upper coupling on the second jack ruptured, expelling the internal parts. One fragment went through Employee #1's upper arm and lodged in his lower abdomen, causing internal injuries.