The city and its fortified surroundings were laid siege to from 12 September to 21 October 1944 by the US 1st Infantry Division with the 3rd Armored Division assisting from the south. Around 13 October the US 2nd Armored Division played their part, coming from the north and getting as close as Würselen, while the 30th Infantry Division played a crucial role in completing the encirclement of Aachen on 16 October 1944. With reinforcements from the US 28th Infantry Division the Battle of Aachen continued involving direct assaults through the heavily defended city, which finally forced the German garrison to surrender on 21 October 1944.