Graduation day took a bittersweet tone at École L'Odyssée in Moncton when the students paid tribute to their classmate who passed away in 2007.

Sean Collins, who died of cancer when he was 13, would have graduated Sunday.

His father, Chris Collins, a Liberal MLA, was asked to address the crowd. He said it was the toughest speech he's ever delivered.

"It reminded me that Sean hasn't been forgotten," he said. "He's still important to these kids and they wanted him with them on their special day."

Sean Collins managed to pack in a lot during his short life.

Two books were written about him, including Ten Needles, which chronicled his battle with cancer. The book raised thousands of dollars for cancer patients.

His story is also featured in a French version of the book, Chicken Soup for the Soul.

Lisette Richard, Sean's mother, said it was an emotional day.

"You know, we were happy to be able to congratulate these kids as well," she said.

A scholarship was presented at the ceremony in Sean Collins' name.