2013 Boston Marathon bombing survivors Paul (C) and J.P. Norden (R) cross the finish line on the one-year anniversary of the bombings in Boston, Massachusetts April 15, 2014. The brothers took part in the final portion of the "Legs for Life Relay", joining family members and friends who walked the entire Marathon route to raise money for children needing prosthetic limbs. US Vice President Joe Biden, other leaders and survivors of the Boston Marathon bombing shared messages of thanks and defiance on Tuesday at a tribute to the three people killed and 264 wounded in the attack exactly one year ago. [Photo/Agencies]