Horrible news from the Boston Marathon, where a pair of explosions was just reported near the race's finish line:

The Daily Beast is running a live-blog.

Update: (On second thought, deleted the TV link. The Bloomberg TV coverage was awful).

(Update: 3:50 PM) Below: the first video footage of the blasts:

(Update: 4:15 PM): this photo (From Boston Globe Sports)

(Update: 4:30 PM)