Ten years ago today, the Confederate Navy submarine H.L. Hunley was raised from the bottom of Charleston harbor in South Carolina, where it sank in 1864.  The Hunley was the first submarine to sink an enemy warship in combat.   A decade after the submarine was raised, there is still no consensus on the cause of the submarine sinking after it attacked and sank the USS Housatonic on blockade duty in Charleston’s outer harbor.

10 years on, mystery of Confederate sub remains

On Friday, scientists announced one of the final steps that should help explain what happened after the hand-cranked sub and its eight-man crew rammed a spar with a powder charge into the Union blockade ship Housatonic off Charleston in February, 1864.

Early next year the 23-ton sub will be delicately rotated to an upright position, exposing sections of hull not examined in almost 150 years.

When the Hunley sank, it was buried in sand listing 45 degrees to starboard. It was kept that way as slings were put beneath it and it was raised and brought to a conservation lab in North Charleston a decade ago.