ພາບຈາກການແຂ່ງແລ່ນ ມາຣາທອນ ທີ່ບອສຕັນ

A State Police Special Response team patrols past posters of encouragement at Wellesley College before the start of the 118th Boston Marathon Monday, April 21, 2014 in Wellesley, Mass. (AP Photo/Mary Schwalm)

5 A State Police Special Response team patrols past posters of encouragement at Wellesley College before the start of the 118th Boston Marathon Monday, April 21, 2014 in Wellesley, Mass. (AP Photo/Mary Schwalm)

Runners in the first wave of 9,000 cross the start line of the 118th Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Stephan Savoia)

6 Runners in the first wave of 9,000 cross the start line of the 118th Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Stephan Savoia)

The second wave of runners make their way down Main Street during the 118th running of the Boston Marathon in Hopkinton, Massachusetts, April 21, 2014.

7 The second wave of runners make their way down Main Street during the 118th running of the Boston Marathon in Hopkinton, Massachusetts, April 21, 2014.

Elite men runners leave the start line in the 118th running of the Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Stephan Savoia)

8 Elite men runners leave the start line in the 118th running of the Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Stephan Savoia)