In the power outage that affected large areas of Southern California last September, most cell phone coverage was completely down for many hours.

Semaphores, smoke signals, and mental telepathy were more useful than cell phones. So were old-fashioned land phone lines.

here on right coast, last year big storms, daughters and I were ONLY able to use texting, and it did work. (And only one of us has land-line.)

a pair of bean cans and piece of string.

I live in Christchurch, New Zealand which has been hit by multiple major earthquakes over the last 20 months (including 5 over magnitude 6). The cell towers here keep working as they have backup battery power, and we found that texts get through when calls won't.

Text messages are part of the communications overhead traffic anyway.

(Text plans are pure profit for cell providers, but that's another story.)

Our office has an instant messanger on all PC's and mobile devices. I have a permanent message that says "I have a phone, a door and email, instant message is one interruption I do not a low."

I hate the intrusion, because they see you are using your keyboard or mouse and they expect you to drop everything and address their needs.

when Loma Prieta hit. Two of us had cell phones at that time but most of them had beepers. Nothing worked for many hours.

In case of a natural disaster, make a plan that includes as little tech as possible.

The cell system is most likely considerably more robust than it was in 1989. But I agree with respect to having a back-up plan. Fortunately for us when our "big one" hit in February 2011 my wife was working right next door to one of our kids' schools and just down the street from the other, so she had them safely rounded up in less than an hour. I was forced to abandon the car and walk home, which took more than two hours from where I work.

For me, that was the worst part of not staying home with them. I gave up a good job in the city to be closer to them because I finally decided the anxiety wasn't worth the money.

You're right about the cell system. Even so, maybe living in earthquake country my whole life, I just don't expect to rely on utilities when things start moving.