Legendary Comedian George Carlin died of heart failure Sunday night.
The dean of counterculture comedians, Carlin constantly pushed the envelope with his jokes, particularly with a routine called "The Seven Words You Can Never Say On TV."  Just last week it was announced that Carlin was being awarded the 11th annual Mark Twain Prize for American Humor.  Carlin had a history of heart trouble.  He died at the age of 71.