General Theodore Roosevelt II, eldest son of Franklin D. Roosevelt, died of a heart attack in his tent in France, approximately one month after the Utah Beach landing, at the age of 56.
Throughout World War II, he suffered from health problems and walked with a cane. He also had heart trouble. On the day of his death he had been selected by General Omar Bradley for promotion to major general and orders had been cut placing him in command of the 90th Infantry Division. These recommendations were sent to General Dwight D. Eisenhower for approval, but when Eisenhower called the next morning to approve them, he had to be told that Roosevelt had died during the night.
He was buried at the American cemetery in Normandy. He now lies next to his younger brother, Lieutenant Quentin Roosevelt. Quentin, a pilot, had been killed in France during World War I and was initially buried at Chamery, but was exhumed in 1955 and moved to the Normandy Cemetery, in order to be re-interred next to his brother.
See also my blog of June 6th: http://thimblefulsofhistory.blogspot.com/2013/06/june-6-d-day-theodore-roosevelt-jr.html