During World War II, Chuuk Lagoon (then known as Truk) was the logistical hub of Japan's operations in the South Pacific theatre. In February 1944, in preparation for the forthcoming Battle of Eniwetok, the United States Navy launched an attack on the atoll. Over the course of two days, a series of airstrikes devastated the Japanese fleet, in an offensive codenamed Operation Hailstone. A total of 50 ships were sunk, although many key Japanese warships had been relocated the week before, and thus escaped destruction.