The MVT (Motor Vehicle Terminal) is an increasingly important form of emergency communications, regardless of what the voice network is doing. When I was an officer in the fire company, we also had direct-to-dispatch phone numbers where we could bypass the radios entirely. For really important stuff (like, "tell the coroner the guy is dead already") we would never go over the air. We also used text messages quite a bit for dispatch details.

And, of course, as comms go digital, they get much harder to deal with and the costs go way, way up.