What is the 'end of watch' that dispatchers make for first responders who die in the line of duty?

Wednesday's memorial service for Burnsville police officers Paul Elmstrand and Matthew Ruge and firefighter-paramedic Adam Finseth will include a final call-out for their badge numbers and a send-off from their fellow officers that includes an assurance their colleagues will carry on the mission.

The ritual is known as an "end of watch" call, a practice that's become commonplace in the last decade as a way to honor the public service of first responders who die in the line of duty.

When Mendota Heights Police officer Scott Patrick was killed during a routine traffic stop in 2014, his funeral ended with a police radio call for Badge 2231, followed by silence and the code 10-7, or "out of service."

"Calling Badge 2231. Officer Scott Patrick is out of service. End of watch, July 30, 2014. 10-7," a dispatcher said.

Department of Public Safety officials say a similar ritual will play out in Eden Prairie for Elmstrand, Ruge and Finseth. The three men were shot and killed while responding to a domestic dispute in Burnsville in mid-February. Thousands have gathered to mourn them in the days since the incident.

Grace Church in Eden Prairie will host a public memorial for the fallen first responders. Members of the public have been invited to line the route of the procession as it makes its way from Eden Prairie to Burnsville. Several neighboring police departments have pledged to send officers who will pay their respects. Minneapolis Police Department officials say 250 of their officers will attend. St. Paul police say about 150 of their officers will also be there.

The memorial begins at 11 a.m. and will be streamed online.