The scientific journal PLOS ONE on Wednesday published an article by researchers who say the men aboard the Confederate submarine H.L. Hunley likely died because their internal organs were crushed by the blast wave caused by the explosion of their torpedo.

The article is available at http://journals.plos.org/plosone.

Today’s Informer features a column originally published on Feb. 17, 2014, the 150th anniversary of the submarine’s loss:

I heard that the Hunley submarine originally got its start in Louisiana and was moved up to the New England states. Is that true? Also, I heard that there was one before it that was sunk in the Gulf of Mexico and they never could find it.

The H.L. Hunley, named for a New Orleans customs official and financier involved in the vessel’s design, was the first submarine to successfully sink an enemy ship in combat.

Horace Hunley and partners James McClintock and Baxter Watson built two other submersible vessels — Pioneer and American Diver — before they constructed the Hunley, which was launched in Mobile, Ala., in July 1863.

Pioneer, launched in early 1862, was built in New Orleans and underwent testing in Lake Ponchartrain. The boat, propelled by two men and a crank system, reportedly sank a schooner and two target barges during its trials and was granted a letter of marque, or permission to operate as a privateer vessel.

But the Union advance on New Orleans scuttled the designers’ plans for Pioneer, and Hunley, McClintock and Baxter, in turn, scuttled the boat in the New Basin Canal and fled to Alabama. The vessel was later raised and studied by the U.S. Navy, which sold the boat for scrap in 1868.

The men launched American Diver — designed for a four-man crew — in early 1863. But it foundered in rough water in Mobile Bay as it was being towed on an attack mission.

The Hunley, launched a few months later, performed well in trials, successfully sinking a target boat using a towed torpedo. It was designed for an eight-man crew and, like the previous vessels, employed a crank system for propulsion.

The boat was shipped by rail that August to Charleston, S.C., which was beset by a Union blockade.

“Following its arrival in South Carolina, the boat experienced a number of operational difficulties. The Army became increasingly unhappy with McClintock’s management of the boat, and as a result seized it, replacing the civilian crew with C.S. Navy personnel,” Rich Wills writes on the website of the Naval Heritage and History Command.

“It was following this transition that the boat was twice accidently lost in Charleston Harbor with fatalities, being both times subsequently salvaged.”

Five of the eight crew members died in the first incident. In the second, the entire crew, including Hunley himself, perished.

Despite the accidents and the loss of life, the Confederate military continued to view the Hunley as a viable boat, and Gen. P.G.T. Beauregard OK’d its use against the Housatonic, a Union blockade ship.

On the night of Feb. 17, 1864, the Hunley set out on patrol and sighted the Housatonic, which was anchored just outside Charleston Harbor. A Union lookout spied the sub as it approached, but the Housatonic was unable to get underway in time to avoid an attack.

The Hunley placed a 2-foot-long torpedo — attached to the end of a 16-foot-long pole — beneath the stern of the sloop of war and detonated the 135-pound gunpowder charge. The explosion caused the ship to burn for several minutes before it sank, killing five Union crewmen.

The Hunley reportedly signaled its success to troops on shore via a lantern, but the sub — and its crew of eight men — sank to the bottom for unknown reasons.

The vessel was discovered in 1995 and was raised in 2000. It is housed at the Warren Lasch Conservation Center in North Charleston, S.C., where it continues to undergo analysis.

For more information, visit https://hunley.org.