It Sank More Than Once
Three attempts were made to retrieve the H.L. Hunley from the bottom of the sea. The retrieval team believe that the ship sank the first time because it got tangled in its rope lines and dragged down under. Once the submarine was repaired, the Hunley set sail again, but one of the crew members failed to close an important valve. The entire ship flooded, which led to the loss of all hands on board as well as the vessel.