She was laid down on 6 May 1944 as a Type C2-S-AJ3 ship under Maritime Commission contract (MC hull 1387) at Wilmington, North Carolina, by the North Carolina Shipbuilding Co.; transferred to the Navy on 30 July and towed to Baltimore on 8 August for conversion to an attack cargo ship by the Key Highway plant of the Bethlehem Steel Co.; and commissioned on 4 December 1944.

After shakedown training in the Virginia Capes area, the attack cargo ship departed Hampton Roads on 5 January 1945 and steamed through the Panama Canal to Hawaii.

On 2 April, a twin-engined Japanese bomber attempted to crash the ship, diving through a storm of anti-aircraft fire.

Upon completion of unloading on 9 April, Tyrrell retired, via Guam and Pearl Harbor, to the West Coast, arriving at San Francisco on 11 May.

Tyrrell next steamed, via Kwajalein, to Saipan where she embarked men and material of the 2nd Marine Division destined for the occupation of Japan.

On the morning of 23 September 1945, Tyrrell arrived off the devastated Japanese port city of Nagasaki and began disembarking her troops and equipment.

After voyage repairs at the Puget Sound Naval Shipyard, she returned to Japan, this time to deliver supplies for the American occupation forces at Kure, arriving there on 10 January 1946.