I keep wondering how safe I would be in Western Queens if a nuke went off in Manhattan.
I'm not so much worried about a suitcase nuke... But, a real nuke could easily be smuggled into the country, VIA Mexico. The NAFTA rules on trucks are very lax and i'm sure a tanker's could be modified to house a nuke inside in the center, then shielf the nuke with lead, and fill the rest of the tanker with whater substance you want... drive it to the border and the customs would let it though... IF they started a truck company and did this to say 20-30 tankers. Its over.
Here is a bomb damage calculator.
http://www.fas.org/main/pu_content_printable.jsp?formAction=156&contentId=367