The sad news broke of James Gandolfini's untimely passing at 51 on Wednesday, to the shock and dismay of many people.

The famed "The Sophanos" actor, who was on a trip with his teenager son at the time, suddenly died in Italy, according to Today. He is being honored at a special commemorative Film Festival in Sicily.

Many fellow actors, directors and colleagues could not believe the news, and are dealing with the immense grief and remembering him.

"He was going to combine [his son's junior high school graduation and soccer championship win] and they were going to spend some time together," said screenwriter and actor, Paul Healy, who met the late star on Friday about an upcoming film that he was set to star. "He was very excited about it. We had a lot of laughs that day. It was really a fun afternoon."

It was Gandolfini's son that called for help after discovering his father had collapsed in their Rome hotel, according to reports. The Emmy-winning star was still alive when the ambulance arrived, said Antonio D' amore, who owns the Hotel Boscolo where they were staying.

After hotel staff rushed into the room to find him, rescue workers tried to resuscitate the actor. He was taken to a nearby hospital before later dying of a reported heart attack.

"Our prayers and condolences go out to Mr. Gandolfini's family and friends," said Michael Kobold, who lived with the actor and considered him a big brother. "We ask you all to respect the family's privacy at this time."

"He was a genius," said "The Sophanos" creator, David Chase. "Anyone who saw him even in the smallest of his performances knows that. He is one of the greatest actors of this or any time."

Edie Falco, his on-screen wife, said "he was a man of tremendous depth and sensitivity, with a kindness and generousity beyond words."

And Jamie Lynn-Sigler, who played his daughter for 10 years, was "heartbroken."

"I spent 10 years of my life admiring and studying one of the most brillant actors, yes, but more importantly one of the greatest men," she said. "Jim had the ability, unbeknownst to him, to make you feel like everything would be alright if he was around. I treasure my memories with him and feel so honored that I was an up close witness to his greatness."

He is sorely missed.