Frank J. Miller entered the military service in Wisconsin. He served in the 10th Mountain Division, 605th Field Artillery Battalion as a Private First Class during World War II. In April 1945 while pursing the German Army along the northern edge of Lake Garda Italy, the Germans destroyed all the tunnels on the lakeside road precluding the 10th Mountain Division from the pursuit. The unit instead conducted an amphibious assault on April 30, 1945 across the lake using DUKW amphibious vehicles.

The 10th Mountain Division assault, lead by Colonel William O. Darby included a DUKW manned by the 605th Filed Artillery Battalion of the division. During the assault, a storm developed and the over loaded DUKW sank killing 25 (including PFC Miller) of the 26 soldiers aboard. The lone survivor was Corporal Thomas Earl “Tom” Hough of Dayton, Ohio. According to Cpl. Thomas Hough, the soldiers desperately tossed their equipment and ammunition overboard in an attempt to keep the vessel from sinking. But the DUKW went down anyway, plunging the men into the frigid waters of the glacier-fed lake. 24 soldiers drowned and their bodies were not recovered. Hough, a former lifeguard from Dayton, Ohio, was rescued by two 10th Mountain soldiers on shore who heard the cries for help, The 24 who perished were commemorated on the Wall of the Missing at the Florence American Military Cemetery. In 2018 the sunken DUKW was discovered and the soldiers are now commemorated on a memorial in Nago-Torbole, Italy.