Reached by phone when he got home from school he described how the incident unfolded between third and fourth periods.

He said he and his friends were hanging outside between periods when another Grade 12 student brought out a knife, threatened people and yelled "white power" before going back into the school. Barnes said a large crowd followed him into the school with many of the students looking for a fight.

"The guy was standing there with a knife in his hand for like two minutes. The teachers that were in the class were just telling everybody to get out, like, freaking out," he said.

"They thought it was a fight, at first."

Barnes said he pulled one of his peers out of the class, looking to de-escalate what was shaping into a fight, but when he got into the hall that's when his friend was stabbed.

"All I heard was 'he got stabbed' and then I looked in the classroom and there's my friend holding his shirt up and blood coming down his stomach."

In a police update on Tuesday afternoon, officers said a male victim has been transported to a trauma centre with serious but non-life-threatening injuries. A male suspect has been arrested and is currently in custody.

Police have not confirmed if this incident was racially motivated or what may have led up to the stabbing.

Brandy Barnes, Tieler's mom, was reached by phone late Tuesday afternoon and said at that time she hadn't yet heard from the police or from the school to tell her what happened. She heard about it first-hand from her son.

She said she doesn't know if she'll be sending Tieler back to school on Wednesday, calling the whole situation "nerve-wracking."

Hearing that the accused called out racist remarks before the stabbing took place was "very disturbing," she said.

Tieler said within his friend group, three are people of colour. He said the Grade 10 student who was stabbed also has white skin.

As of Tuesday evening, police said the investigation is ongoing.