But after 20 minutes had elapsed, he began to wonder where he was.
“What happened inside I don’t know,’’ Viverito said.
“Then the waitress came up and said: ‘Hey, your friend he’s not breathing in the bar -- he’s full of blood,’’’ Viverito said.
“I just ran into the bar and there I saw him lying in the pool of blood.’’
A group of nurses who were dining at the restaurant were trying to resuscitate him and stop the bleeding.
Viverito said he wasn’t even thinking about how he’d gotten hurt at that point.
“That wasn’t even in my mind -- my thoughts were with Chris.’’
Viverito said detectives told him later that a camera inside the bar filmed the incident.
Viverito said he has no idea what could have made the man stab his friend.
“Why?” I mean what’s the point of doing something like that?’’ Viverito said. If you’re mad at somebody just walk away.’’
Viverito began choking up while talking about Pettry's family and three children.
“He was a great guy,'' Viverito said.
On her Facebook page, Pettry's wife Karen said she was shocked by the news and searching for answers.
"I'm so numb and I still can not believe it is true," wrote Karen Pettry. "Today my husband William Christopher Pettry (Most of you only know him by Chris) was taken from his family way too early."
"Some idiot has taken his life. Im so mad, just don't understand why, very lost right now," she wrote. "Please hug the ones you love because you never know if tomorrow you will have that chance."
The killing happened at an Irish-themed restaurant and bar in a development along the St. Johns River in downtown Jacksonville.
The restaurant was busy but not packed early Sunday morning as patrons – many of them in Bears gear – ate and drank while a classic rock cover band played, said Paul Glaser, general manager of Fionn MacCool’s.
Glaser said he was in the dining room when he heard someone yell to dial 911, which he did, he said. The killing happened on a bench in a waiting area near the entrance, Glaser said, and some patrons, including nurses who were in the restaurant, tried to stop the bleeding.
“There was a lot of activity and there was a lot of people that tried to step up and actually save Mr. Pettry’s life,” Glaser said.
The killing marks the first serious violence in what Glaser described as a “family restaurant” since it opened last year, he said. The restaurant is arranging for counselors to talk with any staff members upset by the killing, he said.
Bears coach Lovie Smith extended the team's condolences.
"We had a lot of people that came down to support us. Chris Pettry is one of them," Smith said at a news conference today. "One of our loyal supporters that was killed as he came to Jacksonville to support his favorite team. So our prayers definitely go out to his family."
Tribune reporter Vaughn McClure contributed to this story.