Water breaks can occur at any time, even on days when the temperature dips below -30C, and the windchill makes it even colder.
Such as the case on Fifth Avenue North between Darlington Street and Duncan Street today.
The area is closed to traffic as the City deals with what their Facebook page termed "a serious water main break".
Just before noon Monday crews were undertaking the preliminary work of scraping the build-up of snow and ice off the street.
The City's Facebook page noted; "the street is expected to be closed both today and Tuesday due to the severity of the problem."