 The PRC offensive caught the UN completely by surprise; UN forces realized they would have to fall back, and quickly executed an emergency retreat.UN assets were shuffled in order to cover this retreat, and as part of the force tasked with covering the UN retreat "Missouri" was moved into Hungnam on 23 December to provide gunfire support about the Hungnam defense perimeter until the last UN troops, the U.S. 3rd Infantry Division, were evacuated by way of the sea on 24 December 1950.