Marriott Hotel Explosion

I just looked at CNN.com and found out that there was a large car bombing at the Marriott Hotel in Islamabad, Pakistan. I spent a week there a few years ago while on an assignment for my work and remember meeting some really great people who worked there. Seeing pictures showing a place you've been that has been blown up definitely gives you a strange feeling. I still don't know what would possess a person to want to do such a thing......