Explosions near Boston Marathon finish line

WARNING: GRAPHIC IMAGES Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Medical responders run an injured man past the finish line 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.

WARNING: GRAPHIC IMAGES Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Medical workers aid an injured man at the finish line of the 2013 Boston Marathon following an explosion there Monday, April 15, 2013 in Boston. Two explosions shattered the euphoria at the 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.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES 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.

WARNING: GRAPHIC IMAGES 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.

WARNING: GRAPHIC IMAGES 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/The Boston Globe, John Tlumacki

WARNING: GRAPHIC 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.

WARNING: GRAPHIC IMAGES Medical workers wheel the injured across the finish line during 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.

WARNING: GRAPHIC IMAGES Medical workers aid an injured woman at the finish line of the 2013 Boston Marathon following two explosions there, Monday, April 15, 2013 in Boston. Two bombs exploded near the finish of the Boston Marathon on Monday, killing at least two people, injuring at least 23 others and sending authorities rushing to aid wounded spectators.

WARNING: GRAPHIC IMAGES 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.

WARNING: GRAPHIC IMAGES Women react as they walk from the area where there was an explosion after the Boston Marathon in Boston, Monday, April 15, 2013.

WARNING: GRAPHIC IMAGES A Boston police officer patrols the area near the finish line following 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 Daily Free Press, Kenshin Okubo

WARNING: GRAPHIC IMAGES In this photo provided by The Daily Free Press and Kenshin Okubo, 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.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.

WARNING: GRAPHIC IMAGES Several people have been hurt in two explosions near the Boston Marathon finish line, CBS Boston reports. There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel. It happened around 2:45 p.m. on April 15, 2013 outside Marathon Sports on Boylston Street, according to WBZ-TV's Lis Hughes, who was near the scene covering the marathon. There were two "incredibly powerful explosions just seconds apart," according to Hughes.