TORONTO -- The father of a 12-year-old boy who was struck and killed by a vehicle in Port Hope on Wednesday morning says his son "was the most beautiful boy a parent could wish for."

In a Facebook post on Thursday morning, Brendan Kerin wrote his son Cormac cared so much about others.

"He loved his school, teachers, classmates, friends and teammates. Please know how much he loved you. I can't bring myself to say much more at the moment," Kerin wrote.

"It is too much."

Cormac and his 10-year-old sister were waiting for their school bus on 7th Line, west of Woodvale School Road when they were hit by a northbound vehicle just after 8 a.m.

The boy was pronounced dead on the scene. His sister was airlifted to Toronto's Hospital for Sick Children in critical condition.

"Today, the unthinkable for any parent - happened to our family. In a blink of an eye, our son is dead, and our daughter is fighting for her life at SickKids Hospital," Kerin wrote.

Kerin expressed his appreciation to the first responders and the doctors, saying that his daughter Shea is still alive because of their speedy work.

"All I can say at the moment, Shea needs all of our prayers and thoughts. She is still very much in a precarious situation," he wrote.

Kerin knows that the tragedy has affected many people in the community, including his children's classmates, teachers, teammates and friends.

"We ask that you keep our bus driver and the innocent children on the bus at the time in your thoughts and prayers," he wrote.

"It has been said that peace passes all understanding. Today, our family begins a long and brutal journey to find out what that means."'

On Thursday, a bouquet of flowers was laid on the site of the incident.

Cormac's hockey coach, Mark McDermott, remembers him as a happy, nice boy who was very easy to talk to.

"Unlike a lot of kids who are 12 or 11 years old, he always made sure that when he spoke to you, he looked you right in the eye," McDermott told CTV News Toronto in an interview.

Holding back tears, he said, "I always called the team my kids. I liked having Cormac as one of my kids."

McDermott hopes those who knew Cormac and his family show their support during this difficult time.

"He would want our community to focus on his sister who is still fighting in hospital," McDermott said.

"He would want us to support his mom, his dad, and his older sister because that's the kind of kid he was."