There is a stretch of water off the Pacific island of Guadalcanal that’s officially called Savo Sound, but it has another unofficial name: Ironbottom Sound. It is so named because of the large number of ships and planes, many of them American, lying on the bottom. Some of them got there 71 years ago tonight, on November 30, 1942, during a battle that has come to be known as the Battle of Tassafaronga.

Despite the U.S. Navy’s ultimate dominance of the Pacific during World War II, the Battle of Tassafaronga was a major defeat. It began as an attempt by U.S. naval forces to intercept a fleet of Japanese ships who were ferrying food, in large floating drums, to Japanese soldiers fighting American Marines on land. His ships having spotted the Japanese task force, U.S. Rear Admiral Carleton H. Wright ordered his destroyers to fire torpedoes. They did–but many of the torpedoes were duds who missed their targets. A few of the Japanese ships were hit, and the Takanami was fatally damaged. But the Japanese force was able to respond quickly and in kind, with torpedoes and raking gunfire.

savo sound

This is what “Ironbottom Sound” looked like in August 1942, just before the battle that would give it its (unofficial) name.

The Americans made a lot of mistakes. Some of the ships went the wrong direction, fired their torpedoes at the Japanese too late or too far away to be effective. The defective torpedoes themselves were a major problem–essentially the American ships couldn’t fire back very effectively. The USS Minneapolis was blown up by two Japanese torpedoes. Another torpedo hit the USS New Orleans, blowing off the whole front of the ship. The Japanese also scored direct hits on the Pensacola and Northampton. In all, four ships managed to limp to a U.S. base, burning and heavily damaged. The Northampton wasn’t so lucky. She sank at 3:00 the next morning, December 1, 1942. A total of 395 Americans died in the battle.

The Northampton was one of 32 U.S., British and Australian ships that foundered at Savo Sound between August 1942, when the United States first assaulted Guadalcanal, and February 1943, when the Japanese finally gave up. There are 14 Japanese ships down there too, and a lot of planes. Undersea explorer Robert Ballard, most famous for finding the wreck of the Titanic, explored many of the wrecks in the 1990s.

The U.S. Navy’s defeat at Tassafaronga was one of its lowest points during the Pacific War. Strategically, however, it made little difference. The Japanese couldn’t exploit their victory, and with their troops outnumbered and starving, they finally gave up Guadalcanal a few months later. The momentum of the Pacific War was on the side of the U.S., but it was two and a half more bloody years before the atomic blasts at Hiroshima and Nagasaki convinced the Japanese to throw in the towel.