As far as i know, the missle missed. **** happens. Apearently the building was next to a power station, and the missle missed. Don't let those tv shows fool you with the "we can hit a golf out of someone's hands crap." These weapons may be very expensive, but keep in mind they're still built by the lowest bidder.
I've said it before and i'll say it again. the more complicated you make something the more that can go wrong with it. I mean hell it's hard enough just keeping your PC up to date, and it's software running properly. And your probably the one in charge of making sure it runs right. No offense but i've known a number of the companies that make these products to employ the mentally disabled in the manufacturing proccess. So.... yeah even though you might have einstiens designing these missles when you have little timmy putting the components together, your not exactly ogoing to end up with full proof hardware.
yet this does bring a different question to mind: WTF were UN mine detection personal still doing in Afghanastan? I couldv'e sworn that all the UN personal pulled out the prior week with the other aid people...