Numerous Ottawa residents say they didn't get emergency alerts before a tornado touched down in the east end of the city Sunday evening.
Others say they got official warnings on their cellphones for areas outside the city, after the tornado had already passed.
Canada has a relatively new emergency-alert system that the Canadian Radio-television and Telecommunications Commission says should notify every one with a mobile device connected to an LTE network in the region with the alert.
The tornado, with winds up to 178 kilometres an hour, caught even climate scientists monitoring the weather by surprise.
Ottawa resident Marc Messier, a fire-prevention officer with Ottawa Fire Services, says he was driving when his kids called him separately to tell him about a tornado and didn't get an alert on his phone until after he had stopped and taken a video of the funnel cloud himself.