Boston Marathon

314bb027c9c51c0f520f6a70670053e6.jpg

Runners head to the finish line as the American flag flies in the foreground in the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Charles Krupa)

510c045fa5f9050f520f6a7067002f10.jpg

Runners head down Boylston Street to the finish line of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Robert F. Bukaty)

4f4cbc2da605050f520f6a7067009cc5.jpg

Runners rest at Boston Common after completing in the118th Boston Marathon, Monday, April 21, 2014 in Boston. (AP Photo/Matt Rourke)

b3fc8970a602050f520f6a7067000414.jpg

Men display a Mexican flag as they cheer runners who completed the 118th Boston Marathon, Monday, April 21, 2014 in Boston. (AP Photo/Matt Rourke)

8ebc34aaa601050f520f6a70670058fc.jpg

Cynthia Cirri, of Hamilton, N.J., crosses the finish line of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Elise Amendola)

f122bd2aa600050f520f6a706700138c.jpg

Amputees Jeff Glasbrenner, left, Andre Slay, and Chris Madison cross the finish line of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Elise Amendola)