Sopranos star James Gandolfini died Wednesday in Italy, dpa reported.
The actor, who played abrasive Mafia boss Tony Soprano in the hit TV series, was 51. His death was confirmed by cable network HBO, which produced the hit mafia drama.
Gandolfini was in Italy to attend the 59th Taormina Film Festival in Sicily, the report said. The cause of death was not immediately known but was initially attributed to either a heart attack or stroke.
News of his death prompted an outpouring of tributes on Twitter.
"James Gandolfini was a kind, funny, wonderful guy. I'm so lucky to have worked with him," said actress Olivia Wilde.
"The world just lost one of its great actors," tweeted actor Ewan McGregor, while Senator John McCain said "RIP James Gandolfini, one of the nicest guys I've ever met."