By Jason Allen

SOUTHLAKE (CBSDFW.COM) – A mass casualty training exercise in Southlake Monday gave first responders an opportunity to practice finding potential victims, without ever speaking to them to know their location. Just like a mapping or rideshare app, the SirenGPS app gives location information to public safety officials.

Keller, Southlake, Colleyville and Westlake were part of the annual training event, where this year teams were able to practice communicating with victims through a messaging feature on the application.

The four cities partner for a 911 dispatch operations center called NETCOM. It started utilizing the app in December 2016.

Instead of a standard phone call, users reach 911 through the app. It instantly gives operators the person’s exact location, with GPS coordinates.

NETCOM manager Warren Dudley said Hurricane Harvey underscored the need for such a system. Even with street signs underwater and rescue teams unfamiliar with the area, they would have been able to use coordinates to find people faster.

“Now I can go on here, call the Coast Guard and give them these grid coordinates,” Dudley said. “And say, ‘The call’s coming from these grid coordinates’ and they can put it in their electronics, and go look for this person.”

In Monday’s exercise, potential victims were able to use the messaging feature to tell police where they were in a large building, without having to make any audible noise with a phone call.

NETCOM is averaging about 50 calls a month using the service. Dudley said there have been about 10,000 downloads since the system went online last year.