Believe it or not, the Japanese attack on Pearl Harbor wasn’t the only disastrous event to take place at this historic military installation in the 1940s. Though certainly not as deadly or tragic as the notorious Japanese attack, the West Loch disaster was quite disastrous in its own right. The incident, which occurred Sunday, May 21 at approximately three in the afternoon, began after an explosion in the staging area for Landing Ships, Tanks (LSTs) and other amphibious assault ships in Pearl Harbor’s west loch.

Fire quickly spread among the ships that were being prepared for the invasion of the Japanese-held Mariana Islands - also known as Operation Forager.

U.S. Navy Photograph, U.S. National Archives/Wikipedia

The LSTs - in addition to carrying their own munitions and fuel - were fully loaded with fuel, munitions, vehicles, equipment, and even tanks of high-octane gasoline to aid in deployment once the Mariana Islands were reached.

Army Signal Corps Collection, U.S. National Archives/Wikipedia

Over the course of 24 hours, six LSTs sank, 163 naval personnel were killed, and another 396 were injured, though the numbers are often disputed to this day.

NASA Goddard Space Flight Center/Wikipedia Twenty buildings were also damaged in the explosion.

After the incident, a press blackout was enforced and navy personnel were ordered not to talk about the disaster; the incident was then classified as top secret until 1960.

D Coetzee/Flickr

The Naval Board of Inquiry never quite determined exactly what it was that caused the disaster but did conclude that the explosion was the result of a mortar round aboard LST-353 being detonated during an unloading operation. Rumor has it that the round was either dropped or went off when gasoline vapors ignited.

U.S. Army Signal Corps Photo/Wikipedia

Along with the Port Chicago Disaster two months later, the West Loch incident resulted in major changes in weapon handling practices within the United States Navy.

Army Signal Corps Collection, U.S. National Archives/Wikipedia

The wreckage was cleared quickly and dumped at sea three miles south of Hawaii. The only remnant of the disaster is the hull of the partially beached LST-480, pictured here.

Photographer’s Mate 2nd Class Dennis Cantrell, U.S. Navy/Wikipedia

For more information about Pearl Harbor’s tragedy, take a look at this rare footage from the Japanese attack on Pearl Harbor, as well as these 14 chilling photographs taken on that fateful day.

U.S. Navy Photograph, U.S. National Archives/Wikipedia

Army Signal Corps Collection, U.S. National Archives/Wikipedia

NASA Goddard Space Flight Center/Wikipedia

Twenty buildings were also damaged in the explosion.

D Coetzee/Flickr

U.S. Army Signal Corps Photo/Wikipedia

Photographer’s Mate 2nd Class Dennis Cantrell, U.S. Navy/Wikipedia

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