Thinking out loud here: If it were Islamoterrorism, the Muslims like to time these things on the date of some event in their history with the West— usually when they got their butts kicked. This was the case with both 911 and the Madrid train bombing. The only significant April 15 incident I can come up with just a little research is that today is the anniversary of the first Arab-Israeli battle in 1948 in which the Arabs were defeated. Others here might find other connections.
It's Israel's Independence Day .
John Kerry was just kowtowing to the palestinians a few days ago .
This smells like pally bombs and there are lots of palestinians in and around Boston
Quick pass an amnesty bill that will make these guys all citizens under the guise that it is for Mexicans only .