Where is the building located?
The triplex is located in Montreal's Saint-Henri neighbourhood at 4833-4837, rue Cazelais, near rue Walnut, just below the Ville-Marie expressway.
Firefighters on site.Lorraine Muller | Facebook
When and why did the building collapse?
Montreal firefighters were called to the site on Monday afternoon, around the time of the collapse.
CTV News reported that construction work on a nearby lot caused the building to break down, according to the Service de sécurité incendie de Montréal (SIM).
However, at this point, we don't know much more than that about what caused the incident.
While the owner of the lot reportedly had necessary permits from the City of Montreal for the work, CBC reported that some neighbouring tenants weren't surprised by the debacle, after noticing intense construction for months on end.
According to real estate broker Jason Farinacci, the lot that's under construction is not owned by the same people as the collapsed building. The lot had been expropriated by the government to build the highway before being sold to his client and was then sold again — with Farinacci's help — four months ago.
"I have no idea what the owner/ builder of the new lot did. [...] Did they underpin? Did they not? Was it the engineers? The excavation company? All I know is it's not the owner of the triplex's fault," Farinacci said in an email.
The Sud-Ouest's communications team told us the file has been passed off to the "insurers of the parties involved" who will commission "expert reports" to determine the cause of the collapse and find out who's responsible.
Yikes! Was everyone alright?
Thankfully, no injuries were reported — but some people were evacuated from the area as a precaution.
"It was a huge relief to see that no one was injured. A security perimeter was quickly set up by the borough's teams and all tenants of the affected buildings were relocated either by the owner or by the Red Cross," the Sud-Ouest's mayor, Benoit Dorais, told MTL Blog.
What are people on the Internet saying?
The incident has given Montrealers the opportunity to poke fun at the city's increasingly unaffordable housing market.
"Located in up and coming St.Henri neighbourhood. Open concept. Lots of natural light. Shared backyard. Instant roof access. 2700$ month nothing included. No pets. No guests," wrote Turbo Haüs owner Sergio Da Silva on X (previously Twitter) while captioning a photo of the caved-in building.
Under an Instagram post about the occurrence, @mx_linder commented, "Still gunna sell for 700k as is with these housing market prices."
Is the property really on the market for $1.3 million?
Yes. Before the collapse, the triplex was listed on Centris for an asking price of $1.298 million.
According to the listing, the property had three units: two 4 1/2s and one 5 1/2. It says the ground-floor unit was completely renovated in 2021 while the third-floor apartment was freshly renovated in June of 2023.
Kitchen at 4833-4837, rue Cazelais.Jason Farinacci of RE/MAX ACTION
"The property is obviously coming off the market. It's a total write-off," said Farinacci, who's part of the RE/MAX ACTION team.
"The owner has no idea what is happening at the moment and has devoted her immediate time to finding her tenants lodging and dealing with whatever comes with the aftermath of this unfortunate situation."
Bedroom at 4833-4837, rue Cazelais.Jason Farinacci of RE/MAX ACTION
For more photos of what the property looked like before it crumbled into pieces, you can still find the listing on the RE/MAX-Quebec website.
What happens next?
"These events must be avoided, and landlords have been informed of their responsibility towards their buildings and tenants. What happens next is a matter of private law between the owners. That's why the insurance companies involved are taking over, which will help identify the cause of the collapse," Mayor Dorais said.
How can I help?
In a Saint-Henri community Facebook Group, local artist and musician Dean Eckmann identified himself as one of the building's residents.
"Folks have probably seen tons of photos. Of my life and my partner’s life and belongings sliding out of the house. As far as we know, we have lost everything but what we were wearing Monday," Eckmann posted.
To help get Eckmann and his partner get back on their feet, a friend has set up an online fundraiser with the goal of raising $20,000.
"This space wasn't just a place to live — it was the heart of their lives, filled with memories and treasures. Along with their clothing, furniture, and other possessions, they also lost Dean's meticulously restored historical instruments, as well as the priceless family heirlooms Martin had cherished," wrote Keith Fernandez, the fundraiser's founder.
"Dean and Martin have been moved to a temporary apartment as they try to pick up the pieces. But [...] they need all the support they can get as they try to overcome what seems insurmountable."
Those who wish to contribute can donate via the FundRazr website.
Exterior of the home.Lindsey Shepherd | Coldwell Banker
Loft bedroom.Lindsey Shepherd | Coldwell Banker
Sitting area and dining room. Lindsey Shepherd | Coldwell Banker
Office area and bathroom.Lindsey Shepherd | Coldwell Banker
Updated kitchen. Lindsey Shepherd | Coldwell Banker
Boat launch. Lindsey Shepherd | Coldwell Banker
Gardens on the property.Lindsey Shepherd | Coldwell Banker
Exterior of the front of the home. 
Exterior of the side of the home. 
The black walnut staircase.
The updated kitchen. 
The primary bedroom.
Shutterstock 
Firefighters on site.
Kitchen at 4833-4837, rue Cazelais.
Bedroom at 4833-4837, rue Cazelais.