James Gandolfini, best known for his star turn as mob boss Tony Soprano in the hit HBO series The Sopranos, has died at the age of 51, according to numerous reports. Variety reports that Gandolfini may have died of a possible heart attack in Italy.

Gandolfini won three Emmys for his portrayal of Soprano, the troubled gangster who brought all the sordid elements of Mafia life — family squabbles, blood vendettas, and Bada Bing! — to the psychiatrist's office. The show, spurred by strong performances by Gandolfini and others, helped launch what many consider to be a golden age of television drama.

In addition, Gandolfini had a prolific movie career as a much-admired character actor, recently playing Defense Secretary Leon Panetta in Zero Dark Thirty.

Gandolfini is survived by his wife, Deborah Link, and two children.

In a statement, HBO said, "We’re all in shock and feeling immeasurable sadness at the loss of a beloved member of our family. He was special man, a great talent, but more importantly a gentle and loving person who treated everyone no matter their title or position with equal respect. He touched so many of us over the years with his humor, his warmth and his humility. Our hearts go out to his wife and children during this terrible time. He will be deeply missed by all of us."

Tributes have also poured in from Gandolfini's colleagues in Hollywood.