Several Montreal families are suddenly homeless after a sinkhole was found underneath a historic co-op building that dated back to the 1800s.

The surprise discovery triggered an evacuation on Saturday, with many residents leaving behind personal valuables. In one case, a woman left an urn containing the ashes of her late husband.

Four units of the rent-controlled Griffintown building were demolished Sunday night, leaving many priceless possessions amongst the rubble.

Montreal Mayor Denis Coderre has called on a full report to determine exactly what went wrong, and co-op neighbours say they’ll open their doors to help the displaced families.

“My father has two extra bedrooms, I have one. Even if it’s just a temporary thing to let everybody sleep,” co-op resident Shawn Amyot, who lives in a unit that survived the demolition, told CTV Montreal.

Residents have been temporarily housed in a nearby hotel but will have to find their own lodgings by Tuesday.

The Ste. Anne Co-op is located on Mountain Street in the historic Griffintown neighbourhood, a borough once largely populated by Irish immigrants that has recently become a popular site for new condo developments.

Before the sinkhole was discovered, a nearby construction site was excavating a large hole for a new condo. Officials have yet to determine what caused the sinkhole.

Coderre called the incident “very sad” and said the city must take action.

“We have to do something about it. It’s about people. Was there negligence? Was there a problem? What happened?” Coderre said.

Crack discovered

On April 1, residents say they smelled a broken sewer pipe and later discovered a crack on the outside of the building.

The crack slowly widened until last Friday, when it was determined to be a sinkhole.

The building was promptly evacuated, with residents told to quickly grab their things and leave. But with little time to prepare, many say they left personal items behind.

Urn saved

Resident Nicole Bagnato was among those told to immediately pack up and leave. Even after realizing her husband’s urn was still inside the building, Bagnato was told not to go back inside due to safety concerns.

Fortunately, work crews found the urn unscathed amongst the rubble after the demolition. The ashes of Bagnato’s husband were still safe inside.

Other residents weren’t so lucky.

Jocelyn Marcotte and her sisters lived in the building for 40 years and lost many irreplaceable items in the demolition.

"It was like a shock to us and that's it. We had to leave in quite a hurry, so you grab what you can, like clothes or just leave," Marcotte said.

"Of course we have insurance, but you can never replace what you have. Furniture you can replace, but I'm sorry -- there are things that you can't," she said.

‘An act of God’

The co-op building’s insurance broker has deemed the sinkhole “an act of God” and said it won’t cover the costs of the destruction.

Borough Mayor Benoit Dorais said that while the demolition was unfortunate, it was the only way to ensure residents’ safety.

"The building is actually dangerous and possibility of danger is why the building was evacuated," he said.

The Red Cross has stepped in to assist displaced residents, some of whom were paying less than $400 per month in rent.

But a heritage advocate says that more could have been done to prevent such a loss.

"There's a disconnect between the discourse on heritage and the action on heritage," said Dinu Bumbaru of Heritage Montreal.

With a report from CTV Montreal