On April 15, 2013, at 2:49 pm, an improvised explosive device (IED) detonated near the finish line of the Boston Marathon. Three people died, and more than 260 others needed hospital care, many having lost limbs or suffered horrific wounds. Those explosions began about 100 hours of intense drama that riveted the attention of the nation. The response by emergency medical, emergency management, and law enforcement agencies and by the public at large has now become known colloquially as ”Boston Strong.” This report, through analysis of selected aspects of the Marathon events, seeks lessons that can help response organizations in Boston and other locales improve preparation both for emergencies that may occur at ”fixed” events like the Marathon and for ”no notice” events like those that began with the murder of Officer Collier at MIT and concluded the next day with the apprehension of the alleged perpetrators in Watertown.Accepted Manuscript