Actor James Gandolfini, known to many as Tony Soprano on HBO's The Sopranos, has passed away, according to Deadline. There were initially conflicting reports about cause of death, but an HBO spokeswoman and the actor's manager have cited a possible heart attack. He was 51.

The three-time Emmy winner was reportedly in Italy to attend the Taormina Film Festival.

He recently starred in several films, including the Oscar-nominated Zero Dark Thirty, The Taking of Pelham 123 and Killing Them Softly.