The Civil War submarine Hunley reels backward as a torpedo explodes with the Union warship Housatonic on the evening of February 17, 1864, off Charleston, South Carolina. Seconds earlier, the Hunley crew had speared the ship with a torpedo-tipped iron rod projecting from the submarine's nose.
Before the collision, a lookout on the Housatonic had spotted a bizarre vessel approaching just below the surface—only its coning tower visible—and sounded an alarm. The Housatonic's cannons couldn't be lowered enough to fire at the strange craft, so crewmen used rifles and pistols, but to no avail.
Five minutes after the explosion, the Housatonic was 30 feet (9 meters) under the ocean.
The Hunley—manually powered by seven men—surfaced briefly, so its commander, Lt. George Dixon, could fire flares to signal Confederate officials on shore that the attack had succeeded.
The craft and its crew never returned from its historic mission. Soon after the signal had been fired, the sub sank about 4 miles (6.4 kilometers) off Charleston, where the Hunley remained for 136 years.
(Related: "Gold Jewelry Found in Civil War Sub Hunley.")