In the Pacific War, British, Indian and Australian troops made a disorganised last stand at Singapore, before surrendering on 15 February 1942. The defeat was the worst in British military history. Around 15,000 Australian soldiers alone became prisoners of war. Allied prisoners died in their thousands interned at Changi Prison or working as slave labourers on such projects as the infamous Burma Railway and the Sandakan Death Marches. Australian cities and bases – notably Darwin suffered air raids and Sydney suffered naval attack. U.S. General Douglas MacArthur, based in Melbourne, Australia became "Supreme Allied Commander of the South West Pacific" and the foundations of the post war Australia-New Zealand-United States Alliance were laid. In May 1942, the Royal Australian Navy and U.S. Navy engaged the Japanese in the Battle of the Coral Sea and halted the Japanese fleet headed for Australian waters. The Battle of Midway in June effectively defeated the Japanese navy. In August 1942, Australian forces inflicted the first land defeat on advancing Japanese forces at the Battle of Milne Bay in the Australian Territory of New Guinea.