Pivotal victory from ‘the dungeon’ turned the tide of World War II

It was during the spring of 1942 that the tide of the Pacific War began to shift — not in a battle at sea, it turned out, but in the depths of “the dungeon.”

That was the nickname for the cramped basement space in the Pearl Harbor Naval Shipyard, conceived as a storage room before being converted to an office for Capt. Joseph Rochefort’s “Station Hypo” code-breaking team during World War II.

Rendered cold and damp by the installation of an overzealous air conditioner, the dungeon, as its moniker would suggest, didn’t offer the most luxurious of working environments. While the shadow of Japan’s control over the Pacific grew, the American code-breakers worked day and night in their dark, dank accommodations, desperately hoping to find an advantage against a force of naval precision unlike any they had seen before.

And that’s exactly what they did. Late that April, they cracked the empire’s naval code. On June 4, 1942, a Japanese fleet featuring four aircraft carriers set its sights on Midway, a small coral outpost used by U.S. forces in Hawaii. When they arrived, the forewarned Americans were ready.

“We sank all four [carriers] the first day of the battle,” said 92-year-old Donald “Mac” Showers, the last surviving member of Rochefort’s code-breaking unit. “We were able to do that because we knew where they were, what they were up to and what the schedule was.”

The Battle of Midway, which marks its 70th anniversary Monday, would be the turning point in the Pacific. The U.S. sustained some 300 casualties while the Japanese suffered more than 3,000, and the imperial navy’s aura of invincibility was irrevocably shattered.

“That morning, the Japanese were winning the war,” said Craig L. Symonds, professor of naval heritage at the U.S. Naval Academy in Annapolis. “By that evening, the Americans are winning the war. It’s seldom in history that a battle is so decisive.”

Setting the stage

Before the Battle of Midway, Japan’s drive toward creating its vaunted “Greater East Asia Co-Prosperity Sphere” was meeting with scant opposition. The nation had seized more than a seventh of the Earth’s surface, running rampant through the Western Pacific and the Indian Ocean with attacks on the Philippines, the Dutch East Indies and Australia.

But Japan’s pride was wounded in mid-April, when the Doolittle Raiders, in the first joint operation between the U.S. Army Air Forces and the Navy, struck the Japanese homeland. Although the B-25 bomber attack carried little strategic relevance, it planted a seed of lingering doubt among the Japanese population about the country’s vulnerabilities.

So Isoroku Yamamoto, Japan’s naval leader, decided it was time to close the curtain on the U.S. role in the Pacific Theater, building on the damage inflicted on U.S. forces in the raid six months earlier on Pearl Harbor. Targeting Midway, a two-island atoll about a third of the way from Honolulu to Tokyo, Yamamoto figured the outpost would be tactically crucial to shoring up Japan’s perimeter.

More notably, he also saw the maneuver as a chance to lure the Americans’ remaining aircraft carriers into the open. In doing so, the Japanese could complete the devastation begun at Pearl Harbor.

“Yamamoto decides that he’s going to try to administer the all-out, knockout blow,” said Patrick D. Weadon, curator of the National Cryptologic Museum. “That was the plan. If you were the oddsmaker in Vegas, you would have to give Japan a pretty good shot.”

Battleships had been the focus of conflicts at sea before World War II, but the primacy of the carrier truly emerged in the Pacific. With his knowledge from Station Hypo of the impending strike, Adm. Chester W. Nimitz, the commander in chief of the U.S. Pacific Fleet, found himself weighing whether to send his three carriers out of harm’s way or capitalize on the element of surprise and assail the Japanese armada.

Despite the heavy damage one of those carriers, the USS Yorktown, sustained in the Battle of the Coral Sea, Nimitz made up his mind: The Yorktown, the USS Enterprise and USS Hornet were ordered to Midway.

The Yorktown, in need of months of repairs, was docked at Pearl Harbor and patched together in much prompter fashion. It was a risk, for sure. But Nimitz decided to roll the dice.

“Adm. Nimitz came aboard,” recollected 92-year-old William G. Roy, a photographer on the Yorktown. “He told the captain, ’I need you. You’ve got 72 hours. Get out.”

Breaking the code

Mr. Showers, the code-breaker, was stationed in Seattle when he got home from church on a Sunday in early December 1941, and turned on the radio to learn his country was at war. An Iowa farm boy who had never seen the Navy uniform before enlisting at age 20, Mr. Showers soon found himself under Rochefort’s command, right in the thick of one of history’s most significant naval conflicts.

“I had no idea what I was getting into,” he said.

The United States had cracked Japan’s diplomatic code years earlier, but the naval messages were another matter entirely. Even though the code was never entirely broken, Rochefort’s team deciphered enough bits and pieces to gain a considerable tactical advantage at the Battle of the Coral Sea and, a month later, at the Battle of Midway.

“The Japanese thought that navy code was impenetrable, and they kept the same code all during the war,” Mr. Showers noted. “We had ups and downs in our ability to get hard intelligence, but generally we did pretty well. We relied heavily on that.”

Although Rochefort was confident that the Japanese intended to attack a target classified as “AF,” his superiors were skeptical that the designation referred to Midway. So the U.S. sent a radio message in the clear announcing the atoll was short on drinking water.

Shortly thereafter, an intercepted Japanese message spoke of AF’s decimated water supply. Rochefort’s suspicions were confirmed.

Although breaking the code surely was crucial, it would have mattered little if the execution amid the heat of the battle was lacking. That much, Mr. Weadon points out, was always going to be true.

“Cryptology in warfare is always important,” the museum curator said. “But you have to understand that cryptologists do not win battles. Soldiers, sailors, airmen and Marines win battles. That’s the bottom line.”

A vital triumph

As comprehensive a victory as the Battle of Midway ultimately turned out to be for the U.S. fleet, the clash provided many touch-and-go moments for the American forces.

Early on June 4, the Japanese savaged nearly 100 planes that had taken off from Midway, dealing heavy losses to the Americans while sustaining minimal damage.

Later, when Lt. Cmdr. John C. Waldron led 15 torpedo bombers toward the Japanese fleet, the escorting dive bombers followed the wrong reading and were separated from the pack. All 15 of Waldron’s planes were shot down. Their sacrifice, however, would be key to the U.S. success.

That morning, Lt. Cmdr. C. Wade McClusky’s dive-bomber squadron came upon a lagging Japanese destroyer. Even through the planes had exhausted most of their fuel, McClusky made the decision to follow the ship’s path toward the Japanese fleet.

“By that time, the fuel gauges on those airplanes were well below half-empty,” said Mr. Symonds, the Naval Academy professor. “Most of these pilots are assuming they’re not going to get back. But they’re perfectly willing to accept that responsibility in order to put a bomb on a Japanese carrier.”

Those planes couldn’t have picked a better time to arrive upon the carriers. Preparing to launch an attack on the recently discovered U.S. vessels, the Japanese were caught rearming their aircraft with anti-ship weapons. With their fighter planes drawn near sea level by Waldron’s torpedo bombers, they also were unable to counter McClusky’s high-flying dive bombers.

The circumstances were perfect. In a matter of minutes, three of the four Japanese carriers were struck. They all would sink by the next day.

Not long afterward, the dive bombers’ fuel gauges began to hit empty. But most of the courageous American pilots would be rescued at sea, living to fight another day.

“The machines we could rebuild,” Mr. Symonds said. “The pilots we could not replace.”

The American fleet, though, did not escape unscathed, as the fourth Japanese carrier, the Hiryu, managed to deal a fatal blow to the Yorktown.

There to capture history from the deck was Mr. Roy, who kept his cool and photographed the sinking vessel as the battle raged around him. When it came time to abandon ship, he preserved his three cans of film by taping them under his shirt and life jacket before plunging into the ocean.

“I was in the water for about five or six hours,” Mr. Roy said. “I lost track of time.”

By the time he was rescued, the Yorktown had been avenged. Dive bombers from the Enterprise crippled the Hiryu that afternoon, and the ravaging of Japan’s carriers was complete.

“When you lose your carriers, you can’t land anywhere,” said Hank Kudzik, who was 17 when he served as a gunner’s mate on the USS Nautilus submarine at Midway.”You’re going to run out of fuel; you’re going to land in the water. You’re done.”

Righting a wrong

It was never entirely clear why, but something about Rochefort rubbed the D.C. bigwigs the wrong way.

Perhaps some saw him as an outsider because he didn’t graduate from Annapolis. Or maybe it was the friction he created with Washington when he insisted Midway was the target of the Japanese attack instead of Hawaii or the West Coast.

Whatever the reason, Rochefort was repeatedly recommended by Nimitz for the Distinguished Service Medal — and rejected every time.

It wasn’t until the 1980s, when the code-breakers’ intelligence was declassified, that Mr. Showers spearheaded an effort to finally get the captain the honor he deserved. In 1985, nine years after his death, Rochefort was given the Distinguished Service Medal.

In a ceremony at the White House, President Reagan presented the award to Rochefort’s two children.

“Nimitz said, ’Had it not been for the excellent intelligence I was given, we would have read about the capture of Midway in the morning newspaper,’” Mr. Showers recalled. “And that’s absolutely true.”