Comedian George Carlin, a counter-culture hero famed for his routines about drugs, dirty words and the demise of humanity, died of heart failure at a Los Angeles-area hospital on Sunday. He was 71.

Carlin, who had a history of heart and drug-dependency problems, died at Saint John's Health Center in Santa Monica about 6 p.m. PDT (9 p.m. EDT) after being admitted earlier in the afternoon for chest pains, spokesman Jeff Abraham told Reuters.

Known for his edgy, provocative material developed over 50 years, the bald, bearded Carlin achieved status as an anti-Establishment icon in the 1970s with stand-up bits full of drug references and a routine called "Seven Words You Can Never Say On Television." A regulatory battle over a radio broadcast of the routine ultimately reached the U.S. Supreme Court.

In the 1978 case, Federal Communications Commission vs. Pacifica Foundation, the top U.S. court ruled that the words cited in Carlin's routine were indecent, and that the government's broadcast regulator could ban them from being aired at times when children might be listening.

The Grammy-winning Carlin remained an active presence on the comedy circuit. Carlin was scheduled to receive the John F. Kennedy Center's prestigious Mark Twain Prize for American Humor in November and his publicist said Carlin performed in Las Vegas this month.