It’s a startling sound that had people in Ottawa jumping out of their seats Wednesday.

Environment Canada sent out a tornado warning at 5:36 p.m. Wednesday night to all television, radio stations and wireless providers. But some people say they didn’t get the important message.

“Some phones won’t actually have triggered because it has to be configured properly,” said Peter Kimbell with Environment Canada. “People will observe that some phones triggered and others didn’t and that is unfortunate but that’s the way it is. It is a newer technology, so the newer phones will trigger but the older phones won’t.”

According to Alert Ready, cell phones need the following to trigger in the case of an emergency or amber alert:

• You have an LTE-device like a smartphone (LTE is commonly referred to as “4G LTE”);

• Wireless public alerting (WPA)-compatible; and

• Connected to an LTE cellular network at the time the emergency alert is issued.

The company that actually sends the message says the alert was sent and delivered to radio, television stations and wireless providers within 2.8 seconds. 

"Pelmorex operates the National Alert Aggregation and Dissemination (NAAD) System, which delivers alert messages issued by authorized government agencies to TV, radio, cable or satellite companies, and wireless service providers," said Kurt Eby, Director, Regulatory and Government Relations at Pelmorex in an emailed statement. "For the alert issued on Wednesday by Environment Canada for a tornado threat in the Ottawa area, Pelmorex successfully delivered messages to TV and radio broadcasters, and all wireless service providers."

If your phone did not go off, Alert Ready suggests you contact your service provider to let them know what happened. They are responsible for pushing the alert to the public.

You can also check your phone’s compatibility here:

Environment Canada says it is working on a system that would only send alerts to those directly impacted by a weather event. That, however, will still take a few years.

Environment Canada also says no tornado was ever confirmed.