We don’t know definitively. There are still various loose ends and stories that aren’t totally nailed down. But after a day of reports it now seems possible and actually quite probable that there were only two explosive devices today: the two reported from the start right near the finish line of the marathon.
Authorities appear to have backed off earlier claims about an explosion at the JFK Library and reports that other explosive devices were found in the vicinity of the initial blasts. Again, not definitive. But that’s the surest information that we have at this point.
