 Complete the following phrase:  On 9 December, two days after the Japanese attack on Pearl Harbor, Mississippi departed Iceland, bound for the Pacific Theater. She reached San Francisco on 22 January 1942, where she conducted training and escorted convoys along the west coast over the following seven months. Beginning in May 1942, the original 5-inch51 caliber guns of the secondary battery were removed to make room for anti-aircraft machine guns. On 6 December, she escorted a convoy of troop ships to Fiji, returning to Pearl Harbor on 2 March 1943. Her first major combat operation began on 10 May, when she left Hawaii to support the liberation of the Aleutian Islands. She bombarded Kiska on 22 July, and the Japanese garrison withdrew from the island a few days later. After the conclusion of the campaign, Mississippi returned to San Francisco for an overhaul. On 19 October, she left San Pedro to join the invasion fleet that would attack the Gilbert Islands. During the 