Boston Marathon Bombing

A South Dakota children's chorus made an impromptu performance at the site of the Boston Marathon bombings.

Authorities investigating the deadly bombings at the Boston Marathon 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.

The deadly explosions at the Boston Marathon reverberated on both sides of the Atlantic as cities from Los Angeles to London saw a surge in security.

The boy who was killed in the Boston Marathon bombings was remembered by neighbors Tuesday as a vivacious 8-year-old who loved to run and climb.