April 16, 2013 An expert on terrorism and security says investigators in Boston are looking for minute clues in bomb debris that could point to a suspect, and also turning to race spectators who might have captured evidence. "That was one of the most photographed sites on the planet yesterday," he says.
April 16, 2013 It may take runners a long time to erase the memory of bombs exploding right at the finish line of the Boston Marathon, one of the most celebrated races in the world. But many runners say continuing to run offers a small, symbolic way of putting such violence behind them.
April 16, 2013 News of the deadly bombing attack on the Boston Marathon is echoing in Oklahoma City, where residents will observe the 18th anniversary Friday of the bombing of the Alfred P. Murrah Federal Building. The events include a marathon, which organizers say will still take place.
April 16, 2013 Eight-year-old Martin Richard was killed. His mother Denise and sister Jane were critically injured. It's one of the first tales of tragedy to emerge from the explosions at Monday's Boston Marathon.
April 16, 2013 The Oklahoma City bombing, the Columbine school shootings and the Chernobyl nuclear disaster are among the infamous and sometimes horrific moments that have occurred during the month of April.
April 16, 2013 The investigation into the explosions that killed three and injured dozens continues. We're tracking developments.
April 16, 2013 These days hospitals drill for mass casualty disasters like the explosions at Monday's Boston Marathon. But when it happened for real, the first response was disbelief. Then the victims began arriving. Doctors say they were confronted with the kinds of IED injuries that U.S. troops have gotten in Iraq and Afghanistan.
April 16, 2013 Washington, Los Angeles, New York and San Francisco were among the cities taking action following the blasts.
April 15, 2013 Bill Iffrig, 78, finished second in his division despite being knocked over by an explosion at the Boston Marathon.
April 15, 2013 Even as the shock and horror of the deadly explosions at the Boston Marathon had yet to subside Monday, people were turning to online tools to check on the safety of their friends and family who were at the event. The latest estimates of the casualties include more than 3 dozen people injured, with two dead.
April 15, 2013 President Obama said whoever perpetrated the attack on Boston would feel the full weight of justice.
April 15, 2013 Witnesses say the two explosions were followed by panicked and bloodied spectators as emergency services personnel rushed to the scene.
April 15, 2013 NPR's Dina Temple Raston reports that the FBI has sent counterterrorism officials to the scene. The blasts happened in quick succession four hours after the beginning of the men's race while thousands were still out on the course.