Actor James Gandolfini, star of "The Sopranos,” died Wednesday while on vacation in Italy. He was 51.

The exact cause of death is not known, but his managers said it was possibly a heart attack.

His body is in a hospital morgue in Rome. Once the U.S. Embassy issues a death certificate, Gandolfini’s remains can be returned to the United States.

“It is with immense sorrow that we report our client, James Gandolfini, passed away today while on holiday in Rome, Italy,” managers Mark Armstrong and Nancy Sanders said in a joint statement. “Our hearts are shattered and we will miss him deeply. He and his family were part of our family for many years and we are all grieving.”

The actor had been scheduled to make an appearance at the Taormina Film Fest in Sicily this week.