Among the Allies of World War II what United States armed force did the highest ranking official to die on D-Day serve?
Don Pratt Brigadier General Don Forrester Pratt (July 12, 1892 -- June 6, 1944) was a United States Army officer. He was the assistant division commander (ADC) of the 101st Airborne Division and was the highest-ranking Allied officer killed on D-Day.
William D. Halyburton Jr. William David Halyburton Jr. (October 2, 1924 – May 10, 1945) was a United States Navy hospital corpsman who was killed in action during World War II while assigned to a Marine Corps rifle company. He was posthumously awarded the nation's highest military decoration for valor, the Medal of Honor, for heroic actions "above and beyond the call of duty" on May 10, 1945, during the Battle of Okinawa.