An offshore supply vessel was moored on the port side of a jack up rig. The vessel was moored at the bow with a back down buoy system and the stern was moored to the rig using the bow and port leg ropes. The supply vessel had already worked two other rigs prior to arrival and supply boat deck space was limited. The incident occurred just after the noon tour change when the on tour crane operator resumed cargo operations. Two supply vessel crewmembers were working as riggers on the boat deck. An empty chemical container was back loaded and spotted on the deck of the supply vessel, but as the crane operator started slacking off the hoist wire so the load could be detached, one of the two riggers hand signaled the crane operator to pick up a little so the load could be repositioned (pushed) closer to the other cargo. The crane operator complied by hoisting the container approximately one foot off the deck. As the container cleared the deck it unexpectedly appeared to swing 4 feet to the starboard side of the supply vessel and trapped one of the riggers between the swinging container and a power pack basket setting on deck. The man was crushed
and immediately collapsed onto the deck. The man was transported to the rig’s hospital and the medic performed CPR for approximately 30 minutes however he never regained consciousness, breathing or a pulse.