Battle of Empress Augusta Bay
"Columbia", rejoined her division on 24 September off Vella LaVella, as patrols to intercept Japanese shipping continued. As Marines stormed ashore on Bougainville on 1 November, "Columbia"s guns pounded targets on Buka and Bonis and in the Shortlands. On the night of 2 November, her force intercepted a Japanese group sailing to attack transports lying off Bougainville. In the furious fighting of the Battle of Empress Augusta Bay which resulted, "Columbia" joined in sinking the Japanese cruiser and destroyer , and turning the attackers back from their goal. She continued to support the Bougainville landings and bombard targets in the Solomons through December.