A sign lies on the street as investigators comb through one of the blast sites of the Boston Marathon explosions Wednesday, April 17, 2013, in Boston. Authorities investigating the deadly bombings have recovered a piece of circuit board that they believe was part of one of the explosive devices, and also found the lid of a pressure cooker that apparently was catapulted onto the roof of a nearby building, an official said Wednesday. (AP Photo/Julio Cortez)
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.