CHARLESTON, S.C. - On a clear, moonlight night 150 years ago, the hand-cranked Confederate submarine H.L. Hunley glided out over glassy seas off South Carolina, sailing into history as the first submarine ever to sink an enemy warship.
A century and a half later - and nearly a decade and a half after the sub was raised - just why the Hunley and its eight-man crew never returned is a mystery, albeit one that scientists may be closer to resolving.
Monday marked the 150th anniversary of the Feb. 17, 1864, mission in which the Hunley sank the Union ship Housatonic as the Confederates desperately tried to break the Civil War blockade that was strangling Charleston. While the Housatonic sank, so did the Hunley.
On Monday evening, re-enactors planned a gathering at Breach Inlet between Sullivans Island and the Isle of Palms northeast of Charleston for a memorial service honoring both the Hunley crew and the five Union sailors who died. The loss of life came when the submarine set off a black powder charge at the end of a 200-pound spar, sinking the blockader.
The remains of the Hunley - which was built in Mobile, Ala., and brought to Charleston in hopes of breaking the blockade - were discovered off the coast in 1995.
Five years later, in August of 2000, cannons boomed, church bells rang and thousands watched from the harborside as the sub was raised and brought by barge to a conservation lab in North Charleston. There, scientists have since been slowly revealing the Hunley's secrets.
Among the first artifacts recovered from the silt and sand clogging the inside of the submarine were buttons from the crewmen's uniforms. Later came one of the most sought-after artifacts of the Hunley legend - a gold coin that had deflected a bullet and thus saved the life of Hunley commander Lt. George Dixon at the Battle of Shiloh.
The $20 United States gold piece was given to Dixon by his sweetheart, Queenie Bennett. The words "Shiloh April 6, 1862 My life Preserver" are inscribed on the coin.
One of the initial surprises was that there were eight crewmen, not the nine thought to have been aboard before the Hunley was raised. The remains were found indicating the crewmen were at their positions at the crank. There was no evidence of an attempt to escape through the hatches, raising speculation as to what prevented the Hunley from returning from its mission.
Scientists announced a year ago they may be closing in on exactly what happened.
An examination of the spar found it was deformed as if in an explosion. Scientists now believe the Hunley was less than 20 feet from the Housatonic when it sank. That means it may have been close enough for the sub's crew to have been knocked unconscious by the explosion - long enough that they may have died before awakening.
For years, historians thought the Hunley was farther away and had speculated the crew ran out of air before they were able to return to shore.
Those who went down on the Hunley comprised the third crew of the submarine. Two previous crews died in accidents before the sub could even attempt its mission.
In April of 2004, thousands of men in Confederate gray and Union blue as well as women in black hoop skirts and veils walked in a procession with the crew's coffins from Charleston's waterfront Battery to Magnolia Cemetery. There they were buried near the other crews in what has been called the last Confederate funeral ceremony.