The actor's son Michael, 13, reportedly found his father alive but in distress in the bathroom of their Rome hotel room after the actor suffered an apparent heart attack.
NBC News reports that the teen called for help as his father lay alive but stricken in his room at the Hotel Boscolo around 10 p.m., Antonio D'amore, the hotel's manager, said.
Hotel employees attempted to resuscitate Gandolfini, 51, as they waited for emergency crews to arrive. The actor was still alive when his ambulance arrived at the hospital, but was later pronounced dead at Policlinico Umberto I hospital, located about three minutes away from the hotel, NBC said.
Gandolfini, whose untimely death shocked Hollywood, was visiting Rome on a vacation trip with his son and, it was also said, his sister. He was slated to appear Saturday in an event at the 59th Taormina Film Festival with actress Marisa Tomei. The festival has now planned a special tribute in his memory.
CNN reports that Gandolfini's body remained in a hospital morgue in Rome, awaiting a death certificate from the U.S. Embassy, which will allow it to be returned to the United States.
Dr. Claudio Modini, the emergency room doctor at the hospital where Gandolfini was taken after collapsing, told the Associated Press that the actor arrived around 10:20 p.m. Wednesday and was declared dead at 11 p.m. after efforts to resuscitate him had failed.
Modini said an autopsy would be performed within 24-hours, according to Italian law.
In addition to son Michael, Gandolfini is survived by his wife, Deborah, as well as a 9-month-old daughter, Liliana.