View caption Matt Sayles/AP
Actor James Gandolfini, famously known as Tony Soprano from the HBO series The Sopranos, poses for a portrait in Beverly Hills, Calif. in 2011.
Actor James Gandolfini was famous for his Emmy Award-winning role as mob boss Tony Soprano in the hit HBO series. The cause of death is not yet known with certainty, but HBO says the actor may have suffered a heart attack. He was 51.