Four hours, nine minutes and 43 seconds into the race, the first explosion rocked runners and spectators at the finish line of the 117th-annual Boston Marathon. Then 12 seconds later, a second explosion erupted. The jubilation of completing a grueling 26.2-mile race turned to chaos and terror. Here are some scenes from the catastrophe, one of the nation's worst attacks since Sept. 11, 2001.
Posted 16 April 2013