James Santos was talking to Anastasia De Sousa about her weekend when Kimveer Gill ran into the cafeteria and dropped his carbine on the ground.
"Everyone thought it was a joke. No one reacted immediately," said Santos.
"For me, when I realized he wasn't joking around is when he dropped his firearm on the ground and the distinctive sound of tile and metal."
Gill reloaded his carbine and opened fire, striking Anastasia twice, before a police officer rushed into the cafeteria and cut Gill's rampage short, but he couldn't stop Gill from taking Santos and another man hostage.
"I was 17 years old. I was thinking of others more than myself. For me, I thought it was over," said Santos.
Over the next 20 minutes Gill ranted against police, ordered Santos to look around and tell him where officers were, and threatened to kill himself.
Santos did not expect to survive, but kept trying to engage Gill in conversation.
"I thought, okay, I'm just going to see where this will go. Maybe I could do something, but I think no matter what I'm going to end up being killed," said Santos.
He tried to convince Gill to let him bring Anastasia outside so she could get medical help, to no avail.
After a short time the gunman ordered Santos to stand in front of him as he tried to walk out of the cafeteria.
That's when a police officer shot Gill, and Gill took his own life.
In the months that followed Santos talked about the shooting to anyone who would listen.
A therapist said that he was coping well, and he has moved on.
"I didn't want that day to control the rest of my life. It was an ordeal. It was tragic and it was horrifying but I didn't want that to decide the rest of my future," said Santos.
"I could have. It would have been easier to do that, especially in the beginning, the first couple of times you relive it, you get the cold sweats but eventually, after time, you don't put yourself in that position.
Santos has since served in the military and gone through police training.
He expects to become a police officer within the next year, hopefully in Montreal.
"I wanted to become a police officer before Dawson, but after that incident I knew I wanted to become a police officer," said Santos.
"Ideally I would love and want to work for the same organization, the SPVM, because they sort of gave me another chance."
On the anniversary of the shooting he thinks of De Sousa and what she would be doing today if she had survived.
"It's been ten years. I'm here at this stage of my life, what could have been her stage of life, things like that. I try not to get too emotional but what good will thinking do. I think about it, but what good is it going to do. "
Three officers were awarded the Medal of Bravery, as were two staff members at the school who escorted students out of the cafeteria.
Santos was granted Canada's second-highest civilian award for bravery, the Star of Courage.
Ten years later, Santos feels he did not do anything special.
"I didn't have a plan. I just went with it. So when people say 'Oh you're a hero.' No. If I was a hero no one would have gotten injured or killed," said Santos.