The most plausible situation where I can foresee mass evacuation -- officially sanctioned or not -- is a dirty bomb. The initial blast would be survived by 99.9% of the population but the specter of invisible radiation would freak the rest of us out. I'd certainly be inclined to leave for awhile -- heading west toward the mountains where we frequently camp and where I have a trailer in storage.

I live a few blocks from one of the two major targets.

If I thought about it much I'd have to move. Many of us here assume something bad will happen someday but obviously don't expect it to happen in the next second or this day, or we'd be hitting the road by lunchtime. 9/11/01 was a perfect beautiful blue sky morning. No one imagined at sunrise that day that the Pentagon would be smoldering at sunset.

I posted this query because it is an interesting moral question. Most people in everyday situations, including me, are generous and quick to help. But depending on how such a crisis played out, there could be all kinds of reactions. Most people, I'd guess, haven't given this any thought at all and even those of us who have can't know for sure how we would react in a situation that hasn't unfolded.

It certainly argues once again for being as prepared as possible to grab-and-go. And to be very strategic in packing in advance, because we may well have to make a choice between a box of stuff, a cooler, and a neighbor who wants a lift (with their own stuff in tow, no doubt).

And which neighbor(s)? Would I just grab my dog and purse and take off? Would I check on all my friends? Take the first neighbor who asks for a lift, who I may or may not know well?

99% sure I'd check on my friends (all of whom have cars but may not have much gas) and acquaintances who live on my block. This presumes we're all home when whatever happens.

Something to think about.

I'm encouraged by memories of 9/11, when the roads -- including side streets -- quickly clogged, but drivers were remarkably calm and at least in my neighborhood obeying the traffic lights and stop signs. Perhaps everyone was in shock. Most had a very strong urge to get home -- commuters left ASAP and those of us who live here communed with our neighbors (I took three strangers in for a couple hours, one of whom was hyperventilating in front of my house, having been yelled at by police to run as fast and far as possible - leaving her car in her office garage). My home was walking distance and my car was actually in lock down and inaccessible. This city, on the busiest commuter day of the week - Tuesday - emptied out within a few hours. An unorganized mass evacuation of hundreds of thousands of commuters (residents mostly stayed). The freeways were deserted by late afternoon -- a motorcycle cop that evening told me it was eery.

Let's hope it never happens. Preparation can only go so far.