The website, quoting unnamed law enforcement sources, said that the 66-year-old rocker was found at his Malibu home on Sunday evening unconscious with no pulse.
He had no brain activity when he reached the hospital "and a decision was made to pull life support," the site later said on Twitter.
Petty -- known for hits such as "American Girl," "Don't Come Around Here No More" and "I Won't Back Down" -- just last week had wrapped up a tour to mark 40 years of his band the Heartbreakers.
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