George Carlin, the Grammy-Award winning standup comedian and actor who was hailed for his irreverent social commentary, poignant observations of the absurdities of everyday life and language, and groundbreaking routines like "Seven Words You Can Never Use on Television," died in Los Angeles on Sunday, his publicist, Jeff Abraham, said. He was 71.

The cause of death was heart failure, according to Abraham.

Carlin began his standup comedy act in the late 1950s and made his first television solo guest appearance on "The Merv Griffin Show" in 1965. At that time, he was primarily known for his clever wordplay and reminiscences of his Irish working-class upbringing in New York.

But from the outset there were indications of an anti-establishment edge to his comedy. Initially, it surfaced in the witty patter of a host of offbeat characters like the wacky sportscaster Biff Barf and the hippy-dippy weatherman Al Sleet. "The weather was dominated by a large Canadian low, which is not to be confused with a Mexican high. Tonight's forecast ... dark, continued mostly dark tonight turning to widely scattered light in the morning."

Carlin released his first comedy album, "Take-Offs and Put-Ons," to rave reviews in 1967. He also dabbled in acting, winning a recurring part as Marlo Thomas' theatrical agent in the sitcom "That Girl" (1966-67) and a supporting role in the movie "With Six You Get Egg-Roll," released in 1968.