After operating out of Pearl Harbor and patrolling the Hawaiian atoll, French Frigate Shoals, "O'Brien" called at Midway Island in the latter part of March, escorting the seaplane tender there to evacuate civilians. The two warships returned to Pearl Harbor on 3 April. After an increase and improvement of her antiaircraft batteries, she embarked passengers for transportation to the Naval Air Station at Palmyra Atoll, and then steamed out on 18 April with the destroyers and . The destroyer then joined convoys from San Diego and San Francisco to escort them to American Samoa, arriving at Pago Pago on 28 April.