Sad New Details Emerge Around James Gandolfini's Death

While the tragic news of James Gandolfini's unexpected passing has left his many fans shocked and saddened, new details have emerged about his death.

The 51-year-old was on a boys' trip to Italy with his son, Michael, according to his actor-friend Gilles Marini ("Brothers & Sisters," "Dancing With the Stars"). They were in Rome celebrating the 13-year-old's eighth-grade graduation, and then the "Sopranos" star was expected to attend the Taormina Film Festival in Sicily this weekend and receive the Taormina City Prize.

[Related: Why We Loved Tony Soprano]

The New Jersey-born actor was in his hotel room at the Boscolo Exedra Roma when he became ill at about 10 p.m. local time. Antonio D'Amore, a spokesperson for the five-star hotel, told the "Today" show that the star's son called the reception desk to summon help upon discovering his father in the bathroom after he had apparently suffered a heart attack.

When hotel personnel arrived, Gandolfini was on the bathroom floor with his son by his side, and he was still alive, D'Amore said. Efforts to resuscitate Gandolfini were made and continued as he was driven to the nearby Policlinico Umberto I Hospital.

[Related: James Gandolfini's 20 Best Roles]

Claudio Modini, the director of the Emergency Department of Policlinico, told ABC News that Gandolfini arrived at the hospital in cardiac arrest at 10:20 p.m. Resuscitation efforts continued for 40 minutes, at which point he was pronounced dead. His official time of death was 11 p.m.

The "Zero Dark Thirty" star's cause of death is still undetermined. An autopsy will take place Friday because Italian law stipulates that an autopsy be conducted at least 24 hours after the death occurred.

[Related: 'Sopranos' Co-Stars and More Celebs React to James Gandolfini's Death]

Also, before Italian authorities can release Gandolfini's remains for transport back to the United States, the U.S. Embassy in Rome must issue a death certificate.

TMZ reports that Gandolfini's first wife, Marcy Wudarski, immediately flew to Italy to be with their son.

The actor was married to Deborah Lin Gandolfini, who gave birth to the actor's second child, a daughter, last fall.

See the many sides of Gandolfini's Tony Soprano: