On 7 December 1941 Japanese aircraft made a surprise attack on the US naval base at Pearl Harbor in the Hawaiian Islands. At the same time Japanese forces launched assaults on Thailand, the Philippines and the British colony of Malaya. Three days after Pearl Harbor, two capital ships of the Royal Navy were sunk off the coast of Malaya. This gave the Japanese almost total control of the seas to Australia's north. The sudden fall of Singapore on 15 February 1942 with the rapid, unchecked Japanese advance through the islands of the Netherlands East Indies raised fears of the invasion of Australia. The devastation and high loss of life caused by Japanese air raids on Darwin and Broome early in 1942 underlined the inability of Britain to defend Australia.