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.