My 79-year-old mother tells me that, to this day, the death of President Roosevelt remains one of the seminal events in her life. (This from a woman who experienced a world war, wars in Korea, Vietnam and Iraq, 9/11, moon travel, the fall of Communism and the rise of Ashlee Simpson.)
The common belief was that Roosevelt (already in his fourth term as president) suffered a cerebral hemorrhage and died at his home in Warm Springs, Georgia on April 12, 1945.
Coinciding with the 60th anniversary of his death, Newsweek Magazine has an article questioning the official cause of FDR's death. This is no conspiracy theory, but historians have always questioned the secrecy surrounding FDR's health. This report suggests that Roosevelt may have had cancer.
In this modern age of instant communication via the internet, 24-hour news channels and the Drudge Report, it would be difficult to cover up presidential health issues.