Your grandfather took part in a historically significant battle. White phosphorus grenades and flamethrowers were also used. The allies used AP rounds to shoot through floors and ceilings and would make a dash to the top floor of a building and work their way down— forcing the Germans into a basement. The allies found it safer to shoot bazooka rounds and use explosives to blast entryways known as "mouse holing". This lesson was learned and applied later by soldiers engaged in urban combat in Vietnam— even today as noted in the Baghdadi compound raid.

The German force holding the city was about 18,000 strong. Some of the personnel used as infantry were originally Kriegsmarine intended to crew U-boats (funny how history rhymes, given the use of Navy crews by Russia).