Boston Marathon bombing did not involve an explosive device.
=== One Boston Day ===On the second anniversary of the Boston Marathon Bombings, Mayor Marty Walsh established April 15, the day of the bombings, as an official and permanent holiday called "One Boston Day", dedicated to conducting random acts of kindness and helping others out
 Boston Police Department officer Dennis Simmonds was injured by a hand grenade and died on April 10, 2014

