A 16-year-old boy in Mississauga, Ont., has been charged with aggravated assault after an attack during a school rugby match left another student fighting for life.

Manny Castillo, 15, was critically injured during an attack at a rugby game.
(Courtesy of the Peel District School Board)

Manny Castillo, a Grade 10 student and captain of Lorne Park Secondary School's junior rugby team, is not expected to survive, police said as they announced the charge on Thursday.

Investigators said an altercation took place in the final seconds of a game at the school around 4:45 p.m. ET Wednesday.

"I want to stress that this incident occurred away from the normal game play. It was not as part of one of the plays on the field," said Peel Regional Police Const. J.P. Valade.

Students who witnessed the incident said a rival player picked Castillo up, then drove his head into the ground and beat him until Castillo become unconscious.

Castillo, 15, is being treated for severe head injuries at Toronto's Hospital for Sick Children.

Peel District School Board spokesman Brian Woodland called it "an unbelievably tragic day."

"The kids are deeply affected, you know, in the entire building. We're really spending our day helping kids through, what is for them, a tragic loss," said Woodland.

Grief counsellors were on hand to speak with the students, who gathered in small clusters around the campus talking about the news.

"We haven't cancelled classes, but there is no normal curriculum expectations today," Woodland said.

Castillo's rugby teammates planned to bring cards signed by fellow students to the hospital when they visited the teen Thursday afternoon.

The 16-year-old charged, who cannot be identified under the Youth Criminal Justice Act, was from the competing team.

Peel Region's homicide investigators have taken over the case.