I'm working on my story but I can't think of a reason why the "bad group of people" would have to want to get rid of a certain place. In this story, my character is a secret agent and someone had put a chip in a blackberry phone and if I certain number called it, it'd blow up the town/city. I need reason.
Maybe you can say that these bad people are trying rid the world of all big evil corporations or a specific race of people to name a few examples. Or maybe they are trying to blow up the congress building to get rid of all the congressmen that tweet their private parts to randoms haha.
Why do they have to have a reason? Horrific acts of extreme violence are made much worse when there is no real motivation for it. Instead of asking "why", maybe ask "why not?" Maybe they do it simply because they can.
Or perhaps they are a big corporation themselves, and their greatest competitor's headquarters are located in a certain city? o: /throwingideasoutthere