On 9/11, quite a lot of people walked many miles home from work - in DC and NYC. A number of my friends walked 7-8 miles from downtown DC to their homes in northern Virginia or Maryland. A swift walking pace is 3 mph so it did not take them terribly long to get home but that experience taught my friends to in the future keep comfortable walking shoes in their offices or cars. I live in the city and was struck by the stream of pedestrians that morning who were evacuating on foot to their homes miles away in Maryland - and between here and there were some not-nice neighborhoods.

Those walking were fortunate that 9/11 was a beautiful day - literally not a cloud in the sky and temps in the high-70s. And the attacks were in the morning so people weren't walking in the dark.

Terrorist attack, snow storm (doesn't take much to paralyze this area), power outages or any event that snarls traffic region-wide will be cause for many to walk home from work.

For the past two decades I've lived within one mile of work so haven't been terribly concerned with keeping a BOB in my office. But my vehicle is well-equipped with gear, including a comfortable backpack, Gore-tex hiking boots (socks and extra laces stuffed in each boot), Gore-tex jacket, Gore-tex hats, water bottles, energy bars, headlamp, radio, hiking poles, etc. etc.

The jackets and clothes are adjusted for the season but I've been an outdoors enthusiast long enough to know that an afternoon thunderstorm can turn a hot summer day into a chilly situation.

If I lived several miles or more from my office, I would certainly keep a BOB and hiking boots/socks there and adjust the contents seasonally (always including a Gore-Tex jacket w/hood).

By the way, in confirming the temperature on 9/11/01, I ran across this archive of the CBS morning show that day. A reminder of how quickly a routine day can become a very bad day:

http://archive.org/details/cbs200109110831-0912