Boston Marathon runners Lisa Kresky-Griffin and Tammy Snyder (L) embrace at the barricaded entrance at Boylston Street near the finish line of the Boston
Boston Marathon runners Lisa Kresky-Griffin and Tammy Snyder (L) embrace at the barricaded entrance at Boylston Street near the finish line of the Boston Marathon in Boston, Massachusetts April 16, 2013. Two bombs packed with ball bearings tore through crowds near the finish line of the Boston Marathon, killing three people and triggering a massive hunt for those behind an attack the White House said would be treated as "an act of terror." REUTERS/Shannon Stapleton