What a coincidence.
https://www.facebook.com/SanBernardinoCountyFire/
Yesterday they posted this along with photos...
"County Fire Participates in Active Shooter Exercise
A Battalion Chief and 9 firefighters from the High Desert participated in an active shooter exercise held at Victor Valley Community College on Nov 30. Working closely with our public safety cooperators, firefighters practiced mass-casualty incident (MCI) triage techniques, patient care and safety measures during an active shooter incident, and took this opportunity to test inter-agency communication equipment. SBCoFire personnel are trained and ready to respond to mass-casualty incidents from traffic collisions, to large scale disasters."
I'd believe in such coincidences if this wasn't a common occurrence in large scale attacks. ...I'll put the tin foil away now.