Yorktown (CV-5) was laid down in 1934, launched in 1936 and commissioned in 1937. Following its shakedown cruise in 1938, Yorktown engaged in exercises simulating attacks on the US east coast. After joining the Pacific Fleet in 1939, tactical exercises continued into 1940 and centered on the defense of the Hawaiian islands in the North Pacific. Following the attack on Pearl Harbor in December 1941, Yorktown became the flagship of aircraft carrier Task Force 17, targeting Imperial Japanese Navy garrisons in the Marshall and Gilbert Islands in February 1942 and engaging IJN shipping in the Coral Sea in May 1942. Returning to Pearl Harbor with severe bomb damage that would take three months to repair, Yorktown was back at sea after only three days to mount an attack on the Japanese Navy in the Battle of Midway in June 1942. Yorktown suffered direct hits from Japanese torpedo aircraft but did not sink. Attempts at salvage were interrupted when a final assault by IJN submarine caused Yorktown to eventually capsize and sink on June 7, 1942.