One detail I saw on a report: that in the Watertown firefight, one of these guys threw a bomb towards police and shouted "Fire in the hole!"  That's a phrase popularized in the ongoing TV series Justified.  In the pilot, a white supremacist shouts this as he shoots a rocketlauncher at a black church.  His job in coal mines was explosives, and before setting off the explosives in the mine he would shout Fire in the hole.