Two explosions have left several people dead and many more badly injured at the Boston Marathon finish line on Monday, April 15, 2013.
One of the blast sites on Boylston Street near the finish line of the 2013 Boston Marathon is investigated by a person in a protective suit in the wake of two blasts in Boston, Monday, April 15, 2013. (AP Photo/Elise Amendola)
People look on after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 28 injured after at least two explosions went off near the finish line to the marathon. (Photo by Darren McCollester /Getty Images)
People react to a second explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, John Tlumacki)
People react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, John Tlumacki)
Medical workers aid injured people at the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions near the finish of the Boston Marathon on Monday, killing at least two people, injuring over 20 others. (AP Photo/Charles Krupa)
An unidentified Boston Marathon runner is comforted as she cries in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Elise Amendola)
An injured person is loaded into an ambulance in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston Monday, April 15, 2013. Two bombs exploded near the finish line of the Boston Marathon on Monday, killing two people, injuring 23 others and sending authorities rushing to aid wounded spectators. A senior U.S. intelligence official said two other explosive devices were found nearby. (AP Photo/Elise Amendola)
Medical workers aid an injured man at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two bombs exploded near the finish of the Boston Marathon on Monday, killing two people, injuring 22 others and sending authorities rushing to aid wounded spectators, race organizers and police said. (AP Photo/Charles Krupa)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan)
An unidentified Boston Marathon runner leaves the course crying near Copley Square following an explosion in Boston Monday, April 15, 2013. (AP Photo/Winslow Townson)
People walk near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images)
Runners gather near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images)
A runner sits near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images)
Runners gather near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images)
Runners react near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images)
