"We were worried that he was having a heart attack," says 911 caller

In the final hours of his life, Alan Thicke was doing what he loved: playing hockey with his son.

A lifelong hockey fan, the former Growing Pains star was playing a pickup game with his youngest son, Carter, 19, at a skating rink in Burbank, Calif., when he collapsed.

“We were worried that he was having a heart attack, but he was breathing, he was talking,” Pickwick Gardens vice president Darin Mathewson told KCBS on Tuesday of Thicke, who died at the hospital later that day.

Mathewson called 911 and was with Thicke and his son when the ambulance arrived at Pickwick Ice.

“They got him up on the gurney. They went to take him out. He gave us a thumbs up,” says Mathewson. “He looked at his kid and said, ‘Hey, wait! Take a picture of me. Make sure you get the rink in the background!’ ”

That positive attitude is one familiar to those who had seen Thicke at the rink for years.

“He always had a smile on his face and was so kind to everyone,” a Pickwick Ice regular tells PEOPLE of the actor, who was also father to singer Robin Thicke, 39, and Brennan, 41.

The Pickwick Ice employees tried to maintain that positivity as they comforted Carter.

“We felt bad for Carter, but we trying to be a light for him to at the same point because we didn’t think it was that crazy,” said Mathewson.

Not only did Thicke enjoy partaking in a game of ice hockey, but the veteran actor also actively participated in a game of tennis. For the past 20 years, Thicke has played in Chris Evert’s annual tennis tournament for the past 20 years.

“I told him that he played his best tennis this year,” Evert tells PEOPLE of Thicke, who most recently played in the Chris Evert/Raymond James Pro-Celebrity Tennis Classic gala in Florida.

“His moving was better, he was keeping the ball more, his serve to volley to groundstrokes were consistent. He was certainly coming into his own as a tennis player,” she said. “When I saw him this year I thought he looked ageless, fit, trim, and he had vibrance on his face.”

She said of Thicke, who has been loyal and supportive to her and to her charity organization which began in 1989, “When I saw him this year I thought he looked ageless, fit, trim, and he had vibrance on his face. He had a light I had not seen from him all of these years,” and added, “I saw him three days a year for the 20 years he has played in my tournament, and each year when he returned, he made me feel like I just saw him the day before.”

“He loved his career but he really liked the quality of his family life, he kept those kinds of values all of his life,” said Evert. “He kept his values and truly loved his family … He will be greatly missed.”

Thicke was 69 at the time of his death.