The first successful (after a fashion) submarine, the CSS Hunley, sinks in Charleston Harbor. It was the second time the sub had sunk. Earlier it had gone down in Mobile Bay, killing two of it’s crew.
It was salvaged and transported to Charleston by train, to be used in an attempt to break the Union blockade of that port. The sub’s creator, Horace Hunley, took her out for a test run with a new crew. In front of onlookers, the sub slipped beneath the waves, and never surfaced. Hunley and 7 crewmembers died.
Nonetheless, the sub was once again salvaged and yet another crew took her out in February of 1864. They placed a torpedo (mine) against the USS Housatonic and backed away; the explosive sank the Union ship. But the Hunley never made it back to port, sinking for the final time, taking another crew with her. She was raised in 2000.