Runners in the 118th Boston Marathon disembark a bus as they arrive near the start line Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Stephan Savoia)
Runners cue to board busses ahead of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Matt Rourke)
Runners make their way to load onto busses ahead of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Matt Rourke)
Till T. Teuber of Hamburg, Germany, prepares himself before the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Matt Rourke)