Cause of water main break that flooded Montreal neighbourhood remains unclear: mayor

The mayor of Montreal says the cause of a major water main break Friday morning near the city's Jacques Cartier Bridge remains unknown.

Valérie Plante says 50 buildings were flooded when millions of litres of water erupted onto city streets, and 16 households have asked the Red Cross for emergency housing.

She says workers are now removing debris from roads in the area, but it will take time to get the parts to repair the two-metre-wide pipe.

Plante says she's relieved the city didn't have to shut off the drinking water supply to any customers, although Montreal did issue a boil-water advisory for about 150,000 homes for more than a day.

Chantal Morissette, director of Montreal's water department, says the pipe that burst was among the city's most vulnerable and had suffered corrosion over the years.

Plante also gave an update on the damage caused by torrential rain that hit Montreal on Aug. 9, saying more than 3,300 private buildings and about 60 municipal buildings were flooded.