In December 1941, the Japanese launched a surprise attack on the US naval base in Hawaii. Three hundred and sixty planes of Admiral Nagumo’s fleet set out for Oahu island where they caught the US Pacific fleet moored in Pearl Harbor. Of the 8 battleships present, 3 were sunk, another capsized and the remainder seriously damaged. Three light cruisers, 3 destroyers and other vessels were also sunk or seriously damaged. Of the 500 US planes present only 220 were reparable. By all rights, US forces should have expected the attack – the breaking of the Japanese codes had provided them with ample intelligence saying the attack was imminent. Their failure to do so resulted in one of the greatest disasters in US military history, and a shocking introduction to the war.