A four-storey building being demolished in downtown Montreal collapsed Tuesday, prompting an emergency response from firefighters and police.

The building at 1111-1117 St-Denis St., at the intersection of René-Lévesque Blvd. and opposite the CHUM, had recently been advertised for lease. It was being demolished when a wall gave in, according to an official at the scene.

The incident happened shortly before 5 p.m. A crowd of about a dozen onlookers watched.

The Gazette contacted the city of Montreal but did not receive a reply before publication.

Montreal fire crews hose down the debris at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026.Montreal fire crews hose down the debris at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026. (Evan Buhler/Montreal Gazette) Evan Buhler / Montreal Gazette

Montreal fire crews hose down the debris at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026.Montreal fire crews hose down the debris at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026. (Evan Buhler / MONTREAL GAZETTE) Evan Buhler / Montreal Gazette

An excavator at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026. An excavator at the scene of a building collapse on the corner of René-Lévesque Boulevard and Saint-Denis Street in Montreal on Tuesday, June 23, 2026. (Evan Buhler / MONTREAL GAZETTE) Evan Buhler / Montreal Gazette