Children who should be celebrating the last week of school are instead mourning a classmate killed in a two-vehicle crash that claimed three lives in Mississauga, Ont. Sunday night.

Keziah Edwards Young, 13, was killed in the crash on Winston Churchill Boulevard near the QEW at about 11 p.m. Another child killed in the crash was said to be Keziah’s five-year-old nephew.

According to Peel Police, the Mercedes SUV the children were riding in was struck by a Mazda 6 that had veered into the wrong lane. The 40-year-old man driving the Mazda died at the scene. He was alone in the car.

A 25-year-old woman, believed to be Keziah’s sister and the younger victim’s mother, was taken to hospital in critical condition. A seven-year-old girl is also in stable condition in hospital, with what is believed to be a broken leg. The male driver of the Mercedes suffered minor injuries.

Keziah’s friends said he loved basketball and made them all laugh.

“He's just like someone you would always want to be around. He's just like that person who would make everyone laugh if it's a bad day or anything,” one of his friends told CTV Toronto. “Everyone's just talking about it, about how he's gone. So it's like a really sad day. Just for that to happen. You know someone for so long, next thing he's gone. Just like that.”

Another friend said he couldn’t believe the news.

“I got a phone call and a hung up because I didn't believe that he was gone.”

At Erin Mills Middle School, where Keziah was a Grade 7 student, grief counsellors were helping students and staff Monday while the flag flew at half-mast outside.

“They're looking specifically to those closest to Keziah but also to other friends outside of his closest circle to ensure that everyone has the support that they need today,” said Carla Pereira of the Peel District School Board.

The school was supposed to hold an assembly Monday to recognize student success but that was cancelled and parents were notified of the tragedy.

“I just felt so upset and I can't stop thinking about it because I think of my kids,” said Tricia Hartman, whose son knew Keziah. “It's hard, especially at that age, to explain that to them. I can never imagine the mom, what she's going through right now. As a mom, it would be devastating.”

Elaine Wright says her daughter was friends with Keziah and he frequently played in their neighbourhood.

“You know, I just want to hug my children even longer now and make sure I say I love them before they leave because you just don't know if they're going to come home or not.”

Police have not said whether speed or alcohol were factors in the crash. They have erected a sign at the edge of the road asking witnesses to come forward.

With a report from Sean Leathong, CTV Toronto