Two employees were using a gantry crane to flip a dock (approximately 45 feet long by 4 feet wide) from pontoons side up to pontoons side down. While the dock was at an approximately 45-degree angle, with the pontoons facing down, the injured employee began lowering the dock to the floor using the gantry crane s pendant. He then saw an issue and began to lift the dock back up, to roll the dock backwards and position it vertically. At this point, the rigging slipped out of the gantry crane s hook. When the injured employee began to lower the dock again, the dock fell on top of him, crushing his left ankle and fracturing his right femur.