At fourteen twenty-three hours on the seventh of April, nineteen forty-five, in the East China Sea southwest of Kyushu, the largest battleship ever built rolled onto her side and exploded. One of Yamato's forward magazines went up, and the blast threw a mushroom cloud almost twenty thousand feet into the sky. People in Kagoshima, more than a hundred miles away, reportedly saw it rise. Seventy-two thousand tons of steel and nine eighteen point one inch guns, the heaviest battleship any navy ever completed, were gone. Of her three thousand three hundred and thirty-two men, three thousand and fifty-five went down with her.

No battleship fired a shot at her. What tore her open below the waterline were torpedoes dropped by a big, slow, single-engine bomber that the sailors who worked with it called the Turkey.

The Grumman T B F Avenger went to war for the first time at Midway. Six of them flew into that battle. Five were shot down. The torpedo it carried had an even worse record. In a nineteen forty-one exercise, one torpedo in ten ran the way it was designed to.

Yet over the next three years, this plane put torpedoes into three Japanese battleships, and two of them were the biggest ever built. How did a bomber that lost its first battle become the aircraft that sank Yamato and her sister Musashi? The answer runs through a mountain lake in California, nineteen torpedoes in the Sibuyan Sea, and the last day of Yamato herself. It starts twenty-three hours before the explosion.

Fifteen twenty hours, the sixth of April, nineteen forty-five. Tokuyama, on Japan's Inland Sea. Yamato weighs anchor and steams south with the light cruiser Yahagi and eight destroyers. Vice Admiral Seiichi Ito commands what the Imperial Navy calls the Surface Special Attack Force.

Five days earlier, American troops had landed on Okinawa. In March, when his commanders briefed him on the coming battle, Emperor Hirohito had reportedly asked: But what about the Navy? What are they doing to assist in defending Okinawa? Have we no more ships? This sortie was the Navy's answer, and it was part of the first Kikusui operation, a mass kamikaze attack on the American fleet off Okinawa. Ito's orders were to fight his way through to the American transports off Okinawa's western beaches, run Yamato aground between Higashi and Yomitan, and keep firing as a shore battery until she was destroyed. Her surviving crew were then to go ashore and fight as infantry. There would be almost no air cover. Ito himself believed the plan was futile, and officers on the Navy's own staff called it a waste of men and fuel. The order stood.

Twenty-one forty-four. The American submarine Threadfin, watching the Bungo Strait, radios a detailed sighting report. A second submarine, Hackleback, sights the force as well. Neither boat can get near enough to attack. They do not need to. Off Okinawa, Vice Admiral Marc Mitscher's fast carriers of Task Force fifty-eight now know that Yamato is coming.

What was about to happen to her had been three years in the making, and it began with a failure.

By nineteen thirty-nine, the Navy's torpedo bomber, the Douglas T B D Devastator, was already obsolete. In April nineteen forty, the Navy ordered two prototypes of a replacement from Grumman. The new aircraft first flew on the seventh of August, nineteen forty-one. One of the two prototypes crashed near Brentwood, New York. Production went ahead anyway.

The Avenger was enormous for a single-engine carrier plane. It carried a crew of three: a pilot, a gunner in an electrically powered turret behind the cockpit with a fifty caliber machine gun, and a radioman who also served as bombardier and fired a gun from the belly. Inside the fuselage was a bomb bay big enough for a two thousand pound bomb or a single torpedo. Loaded, it could fly about a thousand miles. Its wings folded back along the fuselage to save space on deck. Pilots said it flew like a truck. Sailors on the escort carriers, comparing it with the nimble Wildcat fighters beside it, called it the Turkey.

The first Avengers almost missed the battle entirely. The detachment of Torpedo Squadron Eight that collected them reached Pearl Harbor the day after its carrier, Hornet, had sailed for Midway. Six of the new planes were flown on to Midway Island instead, under Lieutenant Langdon Fieberling. On the morning of the fourth of June, nineteen forty-two, they were the only Avengers in the battle, and they became the first Navy aircraft to attack the Japanese fleet that day. They went in without fighter cover. Five were shot down. The sixth, flown by Ensign Albert Earnest, made it back with damaged controls, damaged landing gear, his radioman Harry Ferrier still alive, and his gunner dead in the turret. The rest of Torpedo Squadron Eight, flying old Devastators from the carrier Hornet, attacked the same morning. One man from that group survived. None of their torpedoes hit. Midway was won that day by dive bombers, and every American torpedo squadron in the battle suffered heavy losses.

The new plane was not the only problem. The weapon it carried was worse. And the ship it would one day face had been built to survive both.

Yamato had been commissioned on the sixteenth of December, nineteen forty-one, just over a week after Pearl Harbor. She and Musashi were built in such secrecy that American naval intelligence only learned their names in late nineteen forty-two. Its estimates put them at forty thousand to fifty-seven thousand tons, far below the truth. As late as July nineteen forty-five, months after Yamato was gone, American intelligence still credited the class with sixteen-inch guns instead of eighteen point one. Her main armor belt was up to sixteen inches thick, and her turret faces were twenty-six inches. Below the waterline, a torpedo defense system seventeen feet deep, built of void spaces, bulkheads and a lower armor belt, was designed to absorb a charge of eight hundred and eighty pounds of T N T. Inside the hull were eleven hundred and forty-seven watertight compartments.

Oh eight thirty-two, the seventh of April. A Hellcat fighter searching from the carrier Essex finds the Japanese force in the East China Sea. From now on, American aircraft shadow it. At ten fourteen, two big Mariner flying boats join the watch. Yamato turns toward them, opens fire, and misses.

The torpedo those Avengers would carry, the Mark thirteen, was the first American torpedo designed only for aircraft. It was short and fat, ran at thirty-three and a half knots, and carried about six hundred pounds of Torpex, an explosive roughly half again as powerful as T N T. The Navy itself had once doubted the whole idea. In the early nineteen thirties, work on the Mark thirteen was stopped and restarted while the Navy questioned whether torpedo bombers had any future at all. Dive bombers were in favor, and the carrier Ranger was designed with no torpedo storage. In the water the Mark thirteen should have worked. Getting it into the water was the problem. In a July nineteen forty-one exercise, the Enterprise torpedo squadron dropped ten of them. One ran hot, straight and normal. Four sank. Five ran erratically. To have any chance of a good run, a pilot had to release at about fifty feet and around a hundred and ten knots, flying straight, low and slow toward a ship that was firing everything it had. That was the attack that destroyed the torpedo squadrons at Midway.

Two years into the war, little had changed. A study in mid nineteen forty-three of a hundred and five torpedoes dropped at more than a hundred and fifty knots found that thirty-six percent never started their engines, twenty percent sank, and only thirty-one percent made a satisfactory run.

The fix did not come from the fleet. It came from a dam in the mountains of California. The California Institute of Technology used a three hundred foot slide at Morris Dam to launch full-size torpedoes into a lake chosen for its clear water, filming every entry with high-speed cameras. Each weakness was found, redesigned and tested again. Then the improved parts went to Newport, Rhode Island, for forty-three hundred drops from aircraft.

The fixes were two attachments, one at each end. On the nose went a plywood ring known as the pickle barrel. It acted as an air brake, cutting the torpedo's speed through the air by about forty percent, steadying it in flight, and cushioning the blow when it hit the water. Torpedoes now entered the water with so much less damage that pilots could drop them higher and faster. On the tail went a shroud ring, the ring tail, which kept the torpedo running steady instead of hooking, broaching or rolling under the surface.

The Navy's official history of its Bureau of Ordnance noted that the strange new fittings even caught the fancy of the airmen, and it recorded the result in one line: hot, straight and normal runs approached a hundred percent. By the fall of nineteen forty-four, the Navy had authorized torpedo drops from as high as eight hundred feet at up to three hundred knots. On one occasion in early nineteen forty-five, six Mark thirteens were dropped from between five thousand and seven thousand feet, and five of them ran hot, straight and normal.

Mitscher had already acted. Admiral Raymond Spruance, commanding the Fifth Fleet, had ordered Rear Admiral Morton Deyo's battleships, which were bombarding Okinawa, to intercept Yamato. Mitscher, one of the Navy's senior aviators, did not wait. Around ten hundred hours, without telling Spruance until the planes were in the air, his carriers launched two hundred and eighty aircraft from two task groups and a hundred and six more from a third: Hellcat and Corsair fighters, Helldiver dive bombers, and Avengers armed with Mark thirteen torpedoes. The fighters and dive bombers had a job beyond their own hits. The Avengers had to make long, low, straight runs at the target, and every gun that was busy with a strafing fighter or a diving Helldiver was a gun not firing at a torpedo plane. Fifteen carriers launched in all. The air groups from five of them got lost in bad weather and never found the target. Spruance kept Deyo ready with six battleships, seven cruisers and twenty-one destroyers in case the aircraft failed.

Mitscher had reason to trust his aircraft. Avengers had helped sink a battleship before.

On the thirteenth of November, nineteen forty-two, off Guadalcanal, the Japanese battleship Hiei lay crippled after a night battle with American cruisers and destroyers. She had been hit by at least eighty-five American shells, thirty of them eight-inch shells from the cruisers San Francisco and Portland, and with her steering wrecked she was circling at five knots. Army B seventeen bombers attacked her through the morning. At eleven thirty, three torpedoes from Avengers struck her. Torpedo planes from the carrier Enterprise landed at Henderson Field, rearmed, flew back out and hit her with three more. That evening her own destroyers scuttled her, and a hundred and eighty-eight of her men were lost. Hiei was the first battleship Japan lost in the war.

But Hiei was an old ship that surface guns had already broken. The real test came on the twenty-fourth of October, nineteen forty-four, in the Sibuyan Sea, against Yamato's sister, Musashi.

That day two hundred and fifty-nine American carrier aircraft attacked Admiral Kurita's Center Force, and Musashi drew attack after attack. She fired her own eighteen point one inch guns at the incoming planes with special incendiary shells, engaging them from more than twenty-seven thousand yards away. The first Avengers to reach her came from Torpedo Squadron Eighteen on the carrier Intrepid. Lieutenant Junior Grade Raymond Skelly's aircraft took a direct hit on the way in and broke apart, killing its whole crew. At ten thirty, Ensign Willard Fletcher's Avenger, already hit by a five-inch shell, held its run long enough to drop. The torpedo struck Musashi amidships. Fletcher's plane was shot down. Musashi took on three thousand tons of water and listed five and a half degrees. Her damage control teams flooded compartments on the other side and brought her back to one degree.

The Avenger squadrons used a tactic they called hammer and anvil: two groups attacking from both bows at once, so that any turn away from one group turned the ship toward the other. At twelve oh six, nine more Avengers from Intrepid, led by Lieutenant Commander Lloyd Van Antwerp, put three torpedoes into her port side. By early afternoon Musashi was down by the bow and falling behind, and Admiral Kurita slowed his whole fleet to twenty-two knots so she could keep up. The waves kept coming, from Intrepid, Essex, Lexington, Enterprise, Franklin and Cabot. At fifteen fifteen, Avengers from Enterprise under Lieutenant Commander Samuel Prickett hit her three more times, and the departing pilots reported her smoking and heavily down by the bow. At fifteen thirty, a bomb burst in her operations room. It killed fifty-two men and wounded her captain, Rear Admiral Toshihira Inoguchi. Minutes later, Avengers from Franklin and Intrepid hit her with five torpedoes almost at once, three to port and two to starboard.

By sixteen twenty-one she was listing ten degrees to port, with her bow down more than twenty-six feet and her foredeck awash. Her crew moved the wounded and every free hand to the starboard side, dropped the port anchor, and carried stores and timber across the deck to fight the list. At nineteen thirty-six she capsized to port. She had taken nineteen torpedoes and seventeen bombs, and she had stayed afloat for nine hours after the first hit. Of her two thousand three hundred and ninety-nine men, one thousand and twenty-three died, Inoguchi among them.

There was a reason she could take nineteen torpedoes and last so long. The hits had landed on both sides, ten to port and nine to starboard. Each time one side flooded, Musashi's damage control parties flooded the other to keep her level. Spread across both sides, the damage let her stay upright for most of a day.

Against Yamato, the Avengers would do it differently.

Eleven oh seven. Yamato's air search radar picks up a large formation at its maximum range of sixty-three miles. A few minutes later, a delayed report arrives from a lookout station on Kikaigashima: a hundred and fifty carrier planes heading northwest. Eight Hellcats appear and begin circling over the Japanese force, holding contact until the strike arrives. Yamato opens fire, increases speed and begins sharp evasive turns.

Twelve thirty-two. Yamato's lookouts sight the first wave, low and close. Two minutes later she opens fire, and within a minute every gun she has is firing: the nine eighteen point one inch guns throwing special anti-aircraft shells, twenty-four five-inch guns, and a hundred and fifty-two twenty-five millimeter cannon. She runs at flank speed, twenty-seven knots, turning hard.

Twelve forty. Helldivers put two armor-piercing bombs into her aft superstructure. One starts a fire her crew will never put out.

Twelve forty-three. Five Avengers from the carrier Hornet come in low from the port side and drop three torpedoes. One strikes her port bow, and one Avenger is shot down. Yamato takes twenty-three hundred and fifty tons of water, and her damage control teams flood six hundred and four tons into the opposite side to keep her level.

Twelve forty-six. A single torpedo hits Yahagi in her engine room, kills the entire engineering crew and stops her dead. Around her, the destroyer Hamakaze is torpedoed and sinks, and Suzutsuki is set on fire by a bomb. The first wave leaves at twelve fifty. Yamato has taken two bombs and one torpedo, and she is still making flank speed.

Thirteen oh two. Her last working air search radar reports the second wave, fifty aircraft from Essex and Bataan. Twenty minutes later, a Corsair plants a thousand pound bomb on her superstructure.

Thirteen thirty-three. Another hundred and ten aircraft arrive from Yorktown, Intrepid and Langley, and this time every attack is aimed at the battleship. Twenty Avengers come in from sixty degrees off her port bow. Yamato swings to port to meet them. Three torpedoes hit her port side amidships, and her auxiliary rudder jams hard over. Her anti-aircraft fire is still enormous, but each battery is now shooting on its own, with no central control.

Mitsuru Yoshida, a junior officer who survived Yamato's last voyage, wrote about this hour in his book, Requiem for Battleship Yamato. He described the torpedo planes coming in mostly from the port side. Every hit on that one side pushed her further toward capsizing. Musashi had taken her torpedoes on both sides. Yamato was being given no such chance.

She is listing to port, and her damage control teams make the same choice Musashi's crew had made, only far worse. They flood both starboard engine rooms and boiler rooms. The list almost disappears. According to Yoshida, the several hundred men working in those compartments were given no warning before the sea came in. With her starboard engines gone, Yamato slows down.

Two more torpedoes hit her port side, and bombs wreck her upper decks. Her list keeps growing, and her speed falls toward ten knots. Her executive officer reports that every damage control officer is dead and the list can no longer be corrected. Vice Admiral Ito cancels the mission, and at fourteen oh two the order to abandon ship goes out.

Fourteen oh five. Yahagi sinks after twelve bombs and seven torpedoes. At the same time, six Avengers from Yorktown under Lieutenant Thomas Stetson line up on Yamato's starboard side, the side now rising out of the water as she rolls to port. Stetson's crews reset their torpedoes to run at twenty feet. With the ship heeled so far over, those torpedoes strike the bottom of her hull.

Fourteen twenty. Yamato's power fails, and her remaining anti-aircraft guns begin dropping into the sea as she rolls onto her side.

Fourteen twenty-three. She capsizes, and her main turrets break loose. When the roll reaches about a hundred and twenty degrees, one of her two forward magazines explodes.

Less than two hours had passed between the first attack and the explosion. Yamato was hit by at least eleven torpedoes and six bombs. Yahagi and four of the eight destroyers were lost with her. Three of the remaining destroyers picked up survivors. The fourth, Suzutsuki, had lost her bow, and she made it back to Japan by steaming in reverse the entire way. The American cost was ten aircraft and twelve men. It was the last major operation of the Imperial Japanese Navy in the Pacific war.

Musashi had taken nineteen torpedoes and nine hours. Yamato took at least eleven and less than two. The plane was the same type that had been shot out of the sky at Midway. What had changed was everything around it: a torpedo rebuilt at a mountain lake, fighters and dive bombers drawing the fire away from the torpedo runs, and against Yamato, hits concentrated on one side of her hull.

Her armor had been built to stop battleship shells, and she never fought another battleship. The only time she fired her main guns at enemy ships was off Samar in October nineteen forty-four, the day after Musashi sank, and her targets there were American escort carriers and destroyers. Her torpedo defense also had a flaw. The joint between her upper and lower belt armor sat just below the waterline, and it tended to split under a torpedo hit. A single submarine torpedo had already done serious damage to her in nineteen forty-three.

The Bureau of Ordnance history summed up the torpedo that once ran properly one time in ten. It wrote that months before the end of the war, the Mark thirteen was universally accepted as the best aircraft torpedo owned by any nation.

The Avenger outlived its reputation. General Motors built most of them. Grumman had sent the carmaker a complete aircraft held together with sheet-metal screws, so that its automotive engineers could take it apart piece by piece and redesign it for car-style production. In all, nine thousand eight hundred and thirty-nine were built. In the Atlantic and the Pacific, Avengers sank about thirty submarines. One young pilot, George H W Bush, was shot down in an Avenger over Chichi Jima on the second of September, nineteen forty-four. Both of his crewmates were killed. The submarine Finback pulled him from the sea, and forty-four years later he was elected President of the United States.

For the crews on the other side, the cost was counted in thousands. A hundred and eighty-eight men died with Hiei. One thousand and twenty-three died with Musashi. On Yamato, three thousand and fifty-five of three thousand three hundred and thirty-two men died, among them Vice Admiral Ito and Captain Kosaku Aruga, who both chose to go down with the ship. As she rolled over, the suction pulled men in the water back toward her. Roughly a thousand more died aboard Yahagi and the four lost destroyers.

Of the six Avengers that flew from Midway on the fourth of June, nineteen forty-two, one came home. Its radioman, Harry Ferrier, lived until twenty sixteen.

In nineteen eighty-five, a Japanese team in a deep research submersible found Yamato fourteen hundred and ten feet down, broken in two. Her bow lies on its starboard side. Her stern lies upside down, the way she rolled when the Turkey caught up with her.