Gandolfini may have suffered a heart attack, WCPO reported.
Gandolfini was on holiday in Rome when he may have suffered a heart attack, HBO's vice president for program publicity Mara Mikialian told CNN.
Gandolfini was in Italy to attend the 59th Taormina Film Festival in Sicily -- and he was scheduled to participate in a festival event this weekend with Italian director Gabriele Muccino, according to TMZ.com.
He was best known for his award-winning performance as Tony Soprano from the late 1990s to the mid-2000s.
The actor appeared recently in “Zero Dark Thirty” and “The Incredible Burt Wonderstone.” He had been working on Fox Searchlight’s “Animal Rescue” and TV show “Criminal Justice” as well as “Taxi 22.”
Gandolfini won three Emmys for his portrayal of Tony Sprano.
In a statement, HBO called the actor a great talent and a gentle and loving person.