July first, nineteen forty-six. Bikini Atoll, in the Marshall Islands. At nine o'clock in the morning a B twenty-nine named Dave's Dream opens its bomb bay over a lagoon crowded with more than seventy empty warships. The bomb it drops is the same plutonium design that destroyed Nagasaki eleven months earlier. It is aimed at one ship, and that ship has been painted reddish orange, with white gun barrels, so the bombardier cannot miss her.

She is USS Nevada, battleship number thirty-six. She was launched in nineteen fourteen. She fought in the First World War. She was bombed, torpedoed and run aground at Pearl Harbor. She shelled Normandy, Iwo Jima and Okinawa, and took a kamikaze on her main deck. When the war ended, the Navy surveyed her, found her thirty-two years old, and ruled her too old to keep. Her last assignment was to sit still and be destroyed.

The bomb goes off five hundred twenty feet above the lagoon with the force of twenty-three thousand tons of T N T. Five ships sink. Nevada stays afloat. Three weeks later a second atomic bomb explodes underwater in the same lagoon. It rolls the battleship Arkansas onto her side and puts the aircraft carrier Saratoga on the bottom. Nevada stays afloat again. Two years after that, the Navy tows her out of Pearl Harbor and turns the battleship Iowa's guns on her, with a heavy cruiser and a destroyer firing alongside. The shells do not sink her either. In the end an aircraft has to finish her with a torpedo.

So a ship officially too old to serve absorbed two atomic bombs and gunfire from the most powerful battleship the United States ever built. The explanation is not luck, although luck played its part. It begins in nineteen ten, in a Navy design office, with an argument about where to put the armor.

By the summer of nineteen forty-five, the atomic bomb had raised a question that threatened the United States Navy as an institution. If one aircraft carrying one bomb could erase a city, what could it do to a fleet? On August sixteenth, nineteen forty-five, Lewis Strauss, a future chairman of the Atomic Energy Commission, wrote to Navy Secretary James Forrestal. Strauss warned that if a test were not made, there would be loose talk that the fleet was obsolete in the face of this new weapon, and that the talk would cost the Navy the funding it needed after the war.

The Navy had been through this before. In nineteen twenty-one, General Billy Mitchell's bombers had sunk every target ship the Navy offered them, and the headlines had been brutal. This time the admirals wanted the test on their own terms. Vice Admiral William Blandy was given command of Joint Task Force One. His force grew to more than a hundred fifty support ships and forty-two thousand men. The target fleet included four old American battleships, two aircraft carriers, cruisers, destroyers, submarines, transports and landing ships, plus three prizes of war: the Japanese battleship Nagato, the Japanese cruiser Sakawa and the German heavy cruiser Prinz Eugen.

Only seven atomic bombs existed in the world in July nineteen forty-six. Two of them would be spent on these ships. The Assistant Secretary of War, Howard Peterson, put the stakes bluntly. To the public, he said, the test looked like one in which the future of the Navy was at stake.

The test also had a human cost that began before any bomb fell. On February tenth, nineteen forty-six, the military governor of the Marshall Islands, Commodore Ben Wyatt, flew into Bikini to tell its one hundred sixty-seven residents that they would have to leave. They were moved off the atoll aboard a landing ship, most of them to Rongerik. Bikini has never been resettled.

Somebody had to be the bullseye. The planners chose Nevada.

On paper she was the obvious candidate for destruction. Her design had been approved before the First World War. Ten fourteen-inch guns made up her main battery, a generation behind the sixteen-inch guns of the new battleships. Her hull had been flooded at Pearl Harbor, patched, rebuilt in nineteen forty-two, and worn down by three more years of shore bombardment. On December seventh, nineteen forty-one, Japanese dive bombers had hit her at least six times and a torpedo had opened her bow. Sixty of her crew had been killed and a hundred nine wounded. The Navy's own survey in nineteen forty-five judged her too old for the postwar fleet.

The target array made her position worse. Eight ships were anchored within four hundred yards of her. The planners expected a direct hit to sink at least nine vessels, including two battleships and an aircraft carrier, with Nevada at the center of the wreckage. Nobody at Bikini planned for her to come home.

What the planners were judging, though, was a date on a builder's plate. What they were aiming at was a protection scheme that no navy on earth had used before Nevada, and that nearly every American battleship built after her copied.

In nineteen ten, the Navy's General Board concluded that future battles would be fought at very long range, and almost entirely with armor-piercing shells. That conclusion changed everything about how a battleship should be protected. An armor-piercing shell went straight through medium armor plate. Six inches of steel that could not stop a heavy shell was not protection. It was only weight. And at long range, shells would come down steeply onto the deck instead of striking the side, so the deck needed armor as well.

The answer was called all or nothing. Instead of spreading armor thinly across the whole ship, the designers put the thickest possible plate over the parts that kept the ship alive, and left everything else bare. On Nevada that meant a belt thirteen and a half inches thick over the magazines and machinery spaces, seventeen feet tall, with eight and a half feet of it below the waterline. Transverse bulkheads eight to thirteen inches thick closed off each end of the belt. Across the top ran an armored deck three inches thick, built in three layers of special treatment steel. One deck lower sat a second layer, an inch and a half thick, meant to catch fragments from any bomb or shell that burst on the deck above. Its edges sloped down to meet the bottom of the belt.

The result was a sealed steel box running through the middle of the ship. Its designers called it an armored raft. The bow and stern outside it carried no armor at all. They could be riddled, flooded and burned, and the raft was designed to hold enough buoyancy on its own to keep the ship afloat.

The guns inside those turrets fired a fourteen hundred pound armor-piercing shell at two thousand six hundred feet per second. Trials showed that shells fired together from one triple turret interfered with each other in flight and scattered, so the Navy fired the three barrels a tenth of a second apart.

The turrets followed the same logic. Nevada was the first American battleship with three-gun turrets, which saved enough weight to pay for the heavy belt. The triple turret faces were eighteen inches thick. They sat on barbettes of thirteen-inch armor. Her boilers burned oil instead of coal, another first for an American battleship, which removed the coal bunkers earlier designs had relied on as extra protection and made the armored raft all the more necessary.

Nevada was the first ship in any navy built this way. Congress authorized her on March fourth, nineteen eleven. The Fore River Shipbuilding Company took the contract for five million eight hundred ninety-five thousand dollars, not counting armor and guns. She was commissioned on March eleventh, nineteen sixteen.

Pearl Harbor had already tested the idea once. Her captain was ashore that morning. The junior officers aboard, including Ensign Joe Taussig, got steam up and took her away from her mooring while the other battleships burned. Nevada was the only battleship to get underway during the attack, and in the second wave the Japanese dive bombers concentrated on her, hoping to sink her in the channel. They hit her repeatedly. She was deliberately run aground to keep her from sinking in deep water, and she settled on the bottom. Yet the raft held its shape. She was refloated on February twelfth, nineteen forty-two, rebuilt at Puget Sound, and back in action off Attu in May nineteen forty-three. Thirteen months later she was firing on German batteries at Normandy. In February nineteen forty-five she moved to within six hundred yards of the beach at Iwo Jima to support the Marines ashore. On March twenty-seventh, off Okinawa, a kamikaze that had been hit repeatedly by anti-aircraft fire crashed onto her main deck beside turret number three. It killed eleven men, wounded forty-nine, and knocked out both guns in that turret. She stayed on the gun line until the end of June.

The rebuild also left a detail almost nobody knew about. In late nineteen forty-four, the three guns in her number one turret were replaced with guns that had once belonged to USS Arizona. They had been ashore for relining when Arizona exploded at Pearl Harbor. Those guns fired at Iwo Jima and Okinawa. The ship the Navy was about to bomb carried part of the Arizona inside her forward turret.

The Navy surveyors of nineteen forty-five had counted her age correctly. They had not counted what that age was built around.

At nine o'clock on the morning of July first, nineteen forty-six, the B twenty-nine Dave's Dream of the five hundred ninth Bomb Group released the Able bomb over Bikini Lagoon. Major Woodrow Swancutt flew the aircraft. The crew had nicknamed the weapon Gilda, after the character Rita Hayworth played that year, and had stenciled the name on its casing. Every person had been evacuated from the target fleet. The nearest observers watched from support ships at least ten nautical miles away.

Aboard the empty ships were animals placed where sailors would normally stand: guinea pigs, mice, pigs, goats and rats, more than three thousand five hundred in all, on twenty-two of the target ships. On Nevada's open deck stood a goat the scientists had numbered fifty-three. Another, goat number one hundred nineteen, was tethered inside one of her gun turrets, behind armor plate.

Gilda detonated about five hundred twenty feet above the water. It was not over Nevada. The bomb missed its aim point by about seven hundred ten yards and burst west-northwest of her, over the attack transport Gilliam, in far less crowded water. Nevada lay a little over six hundred yards from the point beneath the blast.

Five ships sank: the transports Gilliam and Carlisle, the destroyers Anderson and Lamson, and the Japanese cruiser Sakawa. Fourteen more ships were judged seriously damaged or worse, almost all of them inside a thousand yards. Fires burned across the light carrier Independence.

Nevada's upperworks were heavily damaged. But the armored raft held, and she was still afloat.

The miss started a government investigation. The bombsight was checked and found free of error. Practice drops with dummy bombs landed where they were supposed to. Colonel Paul Tibbets, who had flown the Hiroshima mission, believed the crew had miscalculated. The mystery was never solved.

What the miss could not hide was what the blast had done inside the ship. Goat fifty-three, on the open deck, died of radiation sickness two days after the test. Goat one hundred nineteen, inside the armored turret, lived two days longer, and then it died too. The fireball's radiation had passed through the ship in a few seconds. Nevada had survived the bomb. A crew aboard her would not have. The armor protected the ship. It could not protect the people. A later study of the men who took part in Crossroads found that, on average, their life expectancy had been shortened by three months.

The second test, called Baker, was designed to see what the same weapon could do from below. On July twenty-fifth, the bomb was hung beneath the landing ship L S M sixty, anchored in the middle of the target fleet, ninety feet underwater, halfway to the bottom in water a hundred eighty feet deep. At eight thirty-five in the morning it detonated.

No identifiable part of L S M sixty was ever found. A column of water two thousand feet across rose six thousand feet into the sky, and about two million tons of spray fell back onto the lagoon and the ships in it. The battleship Arkansas, two hundred fifty-nine yards from the blast, had her starboard hull crushed by the underwater shock wave. She rolled over and sank. The aircraft carrier Saratoga, four hundred forty-six yards away, was lifted forty-three feet at the stern and twenty-nine feet at the bow, and seven and a half hours later she slid under. Ten ships were sunk in all. Nagato went down days afterward. Prinz Eugen was towed to Kwajalein and capsized there in December, because she was too radioactive for anyone to repair her leaks.

Nevada was still afloat once more. But this time the damage was of a different kind. The falling spray had soaked every ship in the lagoon with radioactive contamination, and no amount of washing could get it out of her. The Navy cancelled the third planned test, called Charlie, largely because it could not decontaminate the ships left over from the second.

Towed back to Pearl Harbor, the veteran of Pearl Harbor, Normandy, Iwo Jima and Okinawa was decommissioned on August twenty-ninth, nineteen forty-six.

There was still the question of how to dispose of her. She had spent two years as a contaminated hulk when, on July thirty-first, nineteen forty-eight, the Navy towed her sixty-five miles southwest of Pearl Harbor and used her for gunnery practice. The Naval Vessel Register records that Iowa, a heavy cruiser and a destroyer fired on her. Iowa's main battery was nine sixteen-inch guns, each throwing a shell far heavier than anything Nevada's designers had imagined in nineteen eleven.

The gunfire did not sink her. Aircraft were called in, and an aerial torpedo struck her amidships. That hit, below the waterline, finally did what the bombs and the shells had not. USS Nevada went down.

Consider the record the Navy itself wrote. A battleship ruled too old to keep had been the aim point for an atomic bomb and remained afloat. She had ridden out a second atomic bomb that sank a battleship and an aircraft carrier around her and remained afloat again. She had then taken fire from the most powerful battleship in the United States Navy and still remained afloat. Her own service had to use a torpedo to end her.

The explanation lies in the choice the General Board made in nineteen ten. The armored raft gave up protection everywhere except the few places a ship cannot lose. Blast, fire and shells wrecked everything outside that box, the same way the dive bombers had at Pearl Harbor. None of them broke the box open. The aerial torpedo that finally sank her attacked the one place the raft had never been meant to cover, the hull beneath her waterline.

The idea outlived the ship. All or nothing protection, triple turrets, oil-fired boilers and geared turbines all appeared together in Nevada, and nearly every American battleship built after her carried the same features. That included the Iowa that fired on her in nineteen forty-eight. The ship firing the shells was built on the principles first tested in the ship receiving them.

Crossroads also answered the question Lewis Strauss had raised in nineteen forty-five, although not the way anyone hoped. Ships could survive an atomic blast. Their crews could not survive the radiation, and the contaminated ships could not be made safe again. When Congress complained about the four hundred fifty million dollars' worth of warships being destroyed, Admiral Blandy replied that their true value was scrap, at ten dollars a ton, about three point seven million dollars. Nevada had been built for nearly six million dollars before her armor and guns were even counted.

For seventy-two years, nobody knew exactly where she lay. Then on May eleventh, twenty twenty, the maritime archaeology company SEARCH and the robotics firm Ocean Infinity announced that they had found her, sixty-five nautical miles southwest of Pearl Harbor, at a depth of more than fifteen thousand four hundred feet. SEARCH's lead archaeologist, James Delgado, said that Nevada is an iconic ship that speaks to American resilience and stubbornness, and that after rising from her grave at Pearl Harbor she survived torpedoes, bombs, shells and two atomic blasts.

One more piece of her survives above water. One of the Arizona guns that fought in Nevada's forward turret now stands at the Wesley Bolin Memorial Plaza in Phoenix, beside a gun from USS Missouri. They mark where America's Pacific war began and where it ended.

July first, nineteen forty-six. A thirty-two-year-old battleship, painted orange so a bombardier could not miss her, waits alone in the middle of a lagoon for the most powerful weapon ever built. The survey called her too old. The planners called her the aim point. The atomic bomb left her afloat. The second atomic bomb left her afloat. The guns of Iowa left her afloat.

The men who designed her in nineteen ten never imagined an atomic bomb. They only decided to armor the things that mattered, as thickly as they could, and to leave the rest bare. Thirty-six years later that decision carried her through the worst test her Navy could invent. It took a torpedo, fired by her own side, to put her on the bottom of the Pacific.