Have some sources for you to track down background info on your dad and the 313th.Here is the contact info for the 313th alumni group.
Also use the search engine above to find out how you can acquire your dad's IDPF (Individual Deceased Personnel File) Takes some time but usually has a wealth of information regarding the circumstances surrounding the death of your dad.
If you do not have it I would look for a book that details the daily activity of the 79th (and corresponding units) from inception in 1942 to wars end.
313th Inf Regt Mr. Joseph M Napoli Phone 410-668-8469 230 Lyndale Ave BaltimoreMD21236-4220
THE CROSS OF LORRAINE - 79TH INFANTRY DIVISION
Baton Rouge Army & Navy 1946. , 200pp, plates, maps, endpaper maps, Describes the campaign in Northern Europe of the American Divn. which wore the blue and white Croix de Lorraine, the 15th century symbol of triumph adopted to commemorate its victory at Lorraine during WWI. Traces its exploits from reactivation during 1942 at Camp Lugano, Arizona, its deployment in England to its landing on the Cherbourg peninsula D-Day + 8 Details of its push from Cherbourge through Northern France, Belgium to the Rhine are provided by combat records and photographs of the Divn. in action. Includes a complete nominal roll of those who served and a list of citations and awards