But the ride abruptly stopped at about 1:15 p.m., when a dog’s leash became entangled in his bike, according to the Cook County Sheriff’s Police.

Bujak, who was wearing a helmet, according to police, flew off the bicycle and suffered life-threatening injuries to his neck and head, Nowak said.

He was helped by several passers-by, including an off-duty Highland Park firefighter-paramedic who provided him with first aid before the Glenview Fire Department took him to a hospital, according to the sheriff’s police. But Bujak died Wednesday night, according to police and the medical examiner.

Police say the owner of the dog whose leash was entangled in Bujak’s bicycle removed the leash and left. Investigators have not been able to identify the dog’s owner, and are seeking witnesses to the accident to help them sort out what happened, according to Sheriff’s Department spokeswoman Sophia Ansari.

“It’s very unfortunate,” Ansari said. “What we’re looking for now are witnesses.”

Nowak said her father was a week shy of his 69th birthday. She described him as an athletic, healthy man of character who enjoyed life.  Originally from Poland, Bujak has been fascinated with bicycles ever since Nowak can remember. 

“It was always his hobby,” Nowak said, adding that Bujak also enjoyed fixing and making bicycles.

The oldest of Bujak’s three children, Nowak said the family was planning a trip to the Bahamas for Thanksgiving.

“We’ve always done things together,” said Nowak, who also lives in Northbrook and has three children. “He was the most wonderful father, grandfather, husband. He was one of those people who loved life.”

Nowak added that she often rode her bicycle with Bujak on the same trail where he fell. 

“If there is anybody that saw the accident happen, please come forward,” Nowak said. “We’re seeking closure, and we just like to know what happened.”

Ansari asked anyone with information to call the Cook County Sheriff's Police Investigations Unit at 708-865-4896.

achachkevitch@tribune.com