Dozens of firefighters worked to bring a fire under control in downtown Montreal on Monday afternoon.

The Montreal Fire Department (SIM) was onsite around 1:15 p.m. at a vacant building on Saint-Laurent Blvd., near Milton Street.

The building had already been partially taken down and only the front was still standing when the fire broke out.

About 40 to 50 firefighters were able to bring the flames under control by about 3:12 p.m.

The file was transferred to Montreal Police, which could mean that firefighters suspect it is criminal in nature.

Feu de bâtiment -boul. Saint-Laurent et rue Milton – Deuxième alarme – Coupure de courant possible. Merci d’éviter le secteur. pic.twitter.com/HzM5uuz2LB

— Sécurité incendieMTL (@MTL_SIM) April 6, 2026

A large plume of smoke blanketed the neighbourhood after the fire broke out, affecting air quality. Air quality dropped from good to poor during the 1 p.m. reading from the downtown Montreal station.

Traffic was blocked within the area near Ontario, Saint-Dominique, Prince Arthur, and Saint-Urbain Streets.

–This report by La Presse Canadienne was translated by CityNews