"Sopranos" star James Gandolfini died of a heart attack in Rome despite medics battling for 20 minutes to save him, an Italian doctor said Thursday, as tributes pour in for the award-winning US actor.
The New Jersey-born actor, who shot to fame with his portrayal of an emotionally vulnerable mafia boss, had been staying at the Hotel Exedra in the centre of Rome when he fell ill late Wednesday and was rushed to hospital.
"The cause of James Gandolfini's death was a heart attack," Claudio Modini, head of the emergency room at the Umberto I hospital told AFP, adding that the star arrived in hospital at 10:40 pm (2040 GMT).
"He was already dead. After 20 minutes of CPR, time of death was declared at 23:00," he said. An autopsy is due to be carried out on the actor, whose body is being held in the hospital's morgue.
Gandolfini, who won three Emmys and a Golden Globe for his depiction of troubled mob boss Tony Soprano on the popular cable TV series, was in Italy for the Taormina Film Fest in Sicily.
He was to have been awarded the Taormina City Prize by the country's oldest festival, before participating in a roundtable discussion with Italian director Gabriele Muccino this weekend.
The 51-year-old had stopped off in Rome en route to the festival and had spent Wednesday sightseeing with his teenage son Michael, before collapsing in the hotel bathroom, Italian media reports said.
ANSA news agency said Gandolfini had signed autographs in the morning and dined in the hotel in the evening with his son and sister.
It was Michael who had called for help when his father failed to respond, TMNews said.
"At around 22:00 Mr. James Gandolfini, on holiday in Rome and a guest in the hotel Exedra, fell ill while he was in his room. The family contacted staff" who called an ambulance, the hotel said.
HBO, the cable TV channel on which "The Sopranos" aired, issued a statement saying: "We're all in shock and feeling immeasurable sadness at the loss of a beloved member of our family."
The actor had a long film and stage career before lending his heavy stature and big grin to play a depressed mafioso in "The Sopranos," the celebrated series that ran from 1999 to 2007.
ANSA said Gandolfini's first wife, Marcy Wudarski -- Michael's mother -- was on her way to Rome.
The burly actor is also survived by his wife, Deborah Lin, whom he married in 2008 and their nine-month old daughter, according to the Los Angeles Times.
Organisers of the Taormina festival said they were "deeply saddened" to learn of the death of Gandolfini and were planning a special tribute to him.
Organisers Mario Sesti and Tiziana Rocca said the tribute would highlight his "talent and career".
"He was the American actor that better than anyone else has been able to interpret the Italian-American (character) with his personality full of contrasts, ambition, pain, humour," they said in a statement on the festival website.
Gandolfini was born on September 18, 1961. His parents were Italian immigrants -- his father was a bricklayer, and later a high school custodian, while his mother worked in a cafeteria at the same school.
His parents insisted that he go to college, and after some initial resistance Gandolfini graduated with a degree in communications from Rutgers University in 1983.
The future Tony Soprano began acting in the New York theatre, making his Broadway debut in the 1992 revival of "A Streetcar Named Desire" with Jessica Lange and Alec Baldwin.
His breakthrough role came as a hitman in Tony Scott's 1993 "True Romance," which he followed with "She's So Lovely" (1997), "8MM" (1999), "The Mexican" (2001), "The Man Who Wasn't There" (2001) and "In the Loop" (2009).
Last year, Gandolfini played former CIA director Leon Panetta in the Oscar-winning Osama bin Laden manhunt movie "Zero Dark Thirty," while his last big-screen movie was "The Incredible Burt Wonderstone".
Tributes poured in from fellow actors and colleagues, including "The Sopranos" creator David Chase, who called Gandolfini a "genius".
"Anyone who saw him even in the smallest of his performances knows that," he said. "He is one of the greatest actors of this or any time. A great deal of that genius resided in those sad eyes."