The 117-year-old Pioneer bar in Point-Claire was flooded by a leaky water pipe on Sunday.
Ian Ritchie, chief of operations at the Montreal Fire Department, told CBC News that a witness saw the water pouring out of the basement windows at around 8pm. and the notified authorities.
A two-inch tube above the stage inside the bar broke down and led to a significant underground flood, reaching depths of seven to eight feet – almost to the ceiling, he said.
The firefighters had trouble shutting off the water immediately because the valve leading to the building was broken.
Since Monday, it is unclear how much damage was caused by the floods.
According to Save Le Pionnier's Facebook page, an alarm went off all day on Sunday. Authorities pumped water that night, a statement said on the page.
The city of Pointe-Claire must send a team to fix the valve today. The bar has been closed to the public since the summer.
It was on the market for 10 years before being bought by a developer hoping to build four companies and 15 condos in the lot. A demolition warning went up in the building during the summer.
Citizens and patrimonial organizations opposed the plan, saying the building has historical value and complements the village of Pointe-Claire.
In early October, the board rejected the developer's proposal, but the demolition license is valid until March. The developer has until then to send another proposal. If it is suitable to city requirements, it can be approved.