Flowers and signs adorn a barrier at Boylston Street near the of finish line of Monday's Boston Marathon explosions, which killed at least three and injured more than 140, in Boston, Wednesday, April 17, 2013. The bombs that blew up seconds apart near the finish line left the streets spattered with blood and glass, and gaping questions of who chose to attack at the Boston Marathon and why. (AP Photo/Charles Krupa)
Gallery: Bombing investigations and memorials
Apr. 17, 2013 @ 02:17 PM
BOSTON -- Investigators combed through the scene of Monday's explosions in Boston the victims were remembered with memorials and vigils.