Boston-4/15/13- Boston Police officers Rachel McGuire, Kevin McGill and Javier Pagan react to a second  terrorist bomb exploding at the Boston Marathon. They ran after the first bomb exploded next to them near the finish line of the Boston Marathon that knocked down runner Bill Effrig on to Boylston Street.

Boston-4/15/13- Boston Police officers Rachel McGuire, Kevin McGill and Javier Pagan react to a second terrorist bomb exploding at the Boston Marathon. They ran after the first bomb exploded next to them near the finish line of the Boston Marathon that knocked down runner Bill Effrig on to Boylston Street.