[Brett66]

A suitcase nuke isn't even the worst thing that could happen. What if the terrorists got a hold of one of the old Soviet nukes in the multi-megaton range. They could get an armed team of four or five terrorists that could storm any skyscraper in New York, Chicago etc. Then they could carry it to the roof and detonate it for maximum effectiveness. Most of the state would be gone after that.

[HiTech RedNeck]

To get something that size toted to a skyscraper's roof would be quite a feat, storm troopers or no. Something like a hot air balloon would be easier.