In early 1945, the Imperial Japanese Navy made a difficult decision: it would sacrifice the largest, most powerful battleships ever built to protect Okinawa, the gateway to Japan’s Home Islands. The decision sealed the fate of the battleship Yamato and its crew, but ironically did nothing to actually protect the island from Allied invasion.

The battleship Yamato was among the largest and most powerful battleships of all time. Yamato has reached nearly mythical status, a perfect example of Japan’s fascination with doomed, futile heroics. Built in 1937 at the Kure Naval Arsenal near Hiroshima, it was constructed in secrecy to avoid alarming the United States. Japan had recently withdrawn from the Washington Naval Treaty, which limited battleship tonnages, and was free to build them as large as it wanted.

And what ships it built. 839 feet at the waterline and weighing seventy thousand tons fully loaded, Yamato was the largest ship of the war, eclipsed only by postwar American aircraft carriers. It and its sister, Musashi, were armed with nine eighteen-inch naval guns, mounted in turrets of three; six 155-millimeter secondary naval guns; twenty-four five-inch guns; 162 twenty-five-millimeter antiaircraft guns; and four 13.2-millimeter heavy machine guns.

All of this firepower was meant to sink enemy battleships—more than one at a time if necessary. The extremely large number of antiaircraft guns, added during a refit, were meant to keep the ship afloat in the face of American air power until it could close within striking range of enemy ships.

Unfortunately for Yamato and its crew, it was obsolete by the time it was launched in 1941. The ability of fast aircraft carriers to engage enemy ships at the range of their embarked dive and torpedo bombers meant a carrier could attack a battleship at ranges of two hundred miles or more, long before it entered the range of a battleship’s guns. Battleships were “out-sticked,” to use a modern term.

By early 1945, Japan’s strategic situation was grim. Japanese conquests in the Pacific had been steadily rolled back since the Allied landings on Guadalcanal in August 1942. The Philippines, Solomons, Gilberts and Carolines had all been lost and the enemy was now literally at the gates. Okinawa, the largest island in the Ryukyu island chain was the last bastion before the Home Islands itself. The island was just 160 miles from the the mainland city of Kagoshima, coincidentally the birthplace of the Imperial Japanese Navy.

The invasion of Okinawa began on April 1, 1945. In response, the Japanese Navy activated Operation Ten-Go. Yamato, escorted by the cruiser Yahagi (commanded by the famous Tameichi Hara) and eight destroyers, would sail to Okinawa and disrupt the Allied invasion force. Yamato would then beach, becoming coastal artillery. It was a humiliating end for a battleship capable of twenty-seven knots, but the lack of fuel and other military resources made for truly desperate times.

Yamato and its task force, designated the Surface Special Attack Force, departed Tokuyama, Japan on April 6, proceeding due south to transit the Bungo Strait. American forces had already been alerted to the Ten-Go operation, thanks to cracked Japanese military codes, and two American submarines were waiting to intercept the flotilla. Yamato and its escorts were duly observed by the submarines, but the subs were unable attack due to the task force’s high rate of speed and zigzagging tactics. The sighting report was pushed up the chain of command.

Allied naval forces in and around Okinawa were the obvious target, and the massive fleet braced itself accordingly. Six older battleships from the Gunfire and Covering Support Group, or Task Force 54, under Rear Admiral Morton Deyo, prepared to defend the invasion force, but were pulled away in favor of an air attack.

At 0800 hours on April 7, scout planes from Admiral Mitscher’s Fast Carrier Force, or Task Force 58, located Yamato, still only halfway to Okinawa. Mitscher launched a massive strike force of 280 fighters, bombers and torpedo planes, and the fight was on.

For two hours, the Surface Special Attack Force was subjected to a merciless aerial bombardment. The air wings of eleven fleet carriers joined in the attack—so many planes were in the air above Yamato that the fear of midair collision was real. The naval aviators were in such a hurry to score the first hit on the allegedly unsinkable ship plans for a coordinated attack collapsed into a free-for-all. Yamato took two hits during this attack, two bombs and one torpedo, and air attacks claimed two escorting destroyers.

A second aerial armada consisting of one hundred aircraft pressed the attack. As the Yamato started to go down, U.S. naval aviators changed tactics. Noticing the ship was listing badly, one squadron changed its torpedo running depth from ten feet—where it would collide with the main armor belt—to twenty feet, where it would detonate against the exposed lower hull. Aboard Yamato, the listing eventually grew to more than twenty degrees, and the captain made the difficult decision to flood the starboard outer engine room, drowning three hundred men at their stations, in an attempt to trim out the ship.

Yamato had taken ten torpedo and seven bomb hits, and was hurting badly. Despite counterflooding, the ship continued to list, and once it reached thirty five degrees the order was given to abandon ship. The captain and many of the bridge crew tied themselves to their stations and went down with their ship, while the rest attempted to escape.

At 14:23, it happened. Yamato’s forward internal magazines detonated in a spectacular fireball. It was like a tactical nuclear weapon going off. Later, a navigation officer on one of Japan’s surviving destroyers calculated that the “pillar of fire reached a height of 2,000 meters, that the mushroom-shaped cloud rose to a height of 6,000 meters.” The flash from the explosion that was Yamato’s death knell was seen as far away as Kagoshima on the Japanese mainland. The explosion also reportedly destroyed several American airplanes observing the sinking.

When it was all over, the Surface Special Attack Force had been almost completely destroyed. Yamato, the cruiser Yahagi and three destroyers were sunk. Several other escorts had been seriously damaged. Gone with the great battleship were 2,498 of its 2,700-person crew.

The destruction of Yamato was inevitable even as far back as the attack on Pearl Harbor. It was clear that the age of the aircraft carrier had already superseded the battleship, but the insistence of battleship-minded general officers to cling to obsolete military technology undermined Japan’s conduct of the war and sent thousands of Japanese sailors needlessly to their deaths. The story of the Yamato is a warning to all armed forces that the march of war technology is merciless and unsentimental.

Kyle Mizokami is a defense and national-security writer based in San Francisco who has appeared in the Diplomat, Foreign Policy, War is Boring and the Daily Beast. In 2009 he cofounded the defense and security blog Japan Security Watch. You can follow him on Twitter: @KyleMizokami.

This first appeared in December 2016.