Praying for the People in Boston

About all you can do now about the bomb blasts at the Boston Marathon.   Truly horrific... what kind of monster does this?   Innocent people doing something so innocent as running a race.   Who hates us so much to do this?  

I'm really at a loss.

UPDATE:   Here's a link to the video of the actual explosion.   Unbelievably sad and scary.   It's hard to imagine what it must be like for these people to be struggling across the finish line (the timer shows 4:09), which puts them at about a 9:30 mile pace for 26 miles, and then have this happen.