The most prestigious race in the country is also Boston's most popular event. Crowds turn out by the thousands to cheer on the runners of the Boston Marathon. The day had always brought the city together, until the one year two suspects tried to tear it apart. When the Tsarnaev brothers planted bombs at the 2013 race, their horrific act killed three people, and maimed many more. Hear from one of the wounded, an on-scene medic, a trauma surgeon, and law enforcement officers who experienced the sudden terror of this cold-blooded act, and the pursuit of justice that followed.