Whoa guys, you both have a point here. Even if you are at sites that have high threat levels you have no way to know when, if ever, you will have to suffer through the aftermath of any emergency, terrorist attack or not. The folks that didn't get out didn't get the chance, but the thousands of folks in the WTC that responded immediatly to the first impact and put their company's emergency evac plan into effect, or took the initiative and evacuated on their own, joined the 10s of thousands of folks that did not die in the attacks on the WTC but were displaced when the towers collapsed. Then there were the hundreds of thousands of folks who had frightened family. These are the folks that would have benefited from having family emergency plans.
My company had folks working at JFK airport and one of my guys was on the cell phone to me watching it while the WTC attack occured. We immediately decided to evacuate from the airport and tried to get our folks back to their homes, and families, before the roads became clogged and the tunnels, bridges, and ferrys got shut down. Very shortly all local cell and land line communication was clogged and the only way that my coworkers could get word to their families was for us to relay messages that they were safe via long distance (odd how we could get through after a few tries using long distance, but they couldn't make local calls effectively). They used the bottled water they had taken with them over the hours as they inched through traffic.
As to weapons, other than what you carry on a day to day basis for personal defence, you should have nothing to worry about.