City of Lachute firefighters were requested in late noon on the way to a fire broke out on Argenteuil road for the roof of the high school.
It appears that the fire started in the ventilation system of the building of three floors, immediately in the classroom students and staff were evacuated, and City of Lachute fire departement sounded a general alarm.
Fire departments of town of St-Colomban, St-André d'Argenteuil, Mirabel, Brownsburg-Chatham and even Hawkesbury (Ontario) came to support their colleagues in Lachute.
Dozens of firefighters worked for hours to contain the flames already in progress when they arrived.
In the late afternoon, the fire was under control.
Damage to the building could be quite important given that firefighters had to punch the roof in several places to put the different fires.
The versatile High school has about 2000 students.
Nobody was injured.