[toast0]

> When the entire San Diego region lost power during rush hour for 4 hours in 2011, the cell phone system still worked. I was able to email documents to Tokyo from a car despite no traffic lights.

Around me, cell towers have 3-5 hours of battery when utility power is out. If your outage had gone on much longer, you would likely have seen cell towers start dropping out.

Of course, my area also has some other nasty SPoFs. A couple years ago, a telco cable was severed and DSL for everyone was out and at least some of the cell towers were live, but no service. A few weeks ago, the cableco had its wires severed, and cable tv and internet was offline, and so were some cell towers. IIRC, for the telco one t-mobile worked and verizon didn't, and for the cableco t-mobile didn't work and verizon did. Not sure about at&t.