Surviving a Terrorist's Nuclear Attack
Interesting reading, mostly for the probable effects of a terrorist-sized nuclear bomb.
A terrorist bomb is likely to be relatively small—possibly only a fraction of the Hiroshima bomb’s explosive power—and likely exploded at ground level. This means that the area totally destroyed by the explosion is likely to be much smaller than the area exposed to lesser damage or to fallout radiation (this nuclear weapons effects calculator from the Federation of Atomic Scientists will let you see the effect of different sized bombs burst at different heights). Because of this, Homeland Security people in the Obama Administration have been encouraging a duck-and-cover approach, followed by advice to “shelter in place” against fallout rather than trying to evacuate the area.