An injured man is loaded into an ambulance after two bombs went off near the finish line of the Boston Marathon on April 15, 2013. Three people were killed and at least 264 were injured.
An injured man is loaded into an ambulance after two bombs went off near the finish line of the Boston Marathon on April 15, 2013. Three people were killed and at least 264 were injured.
Jim Rogash/Getty Images
A man comforts a victim on the sidewalk at the scene of the first explosion.
A man comforts a victim on the sidewalk at the scene of the first explosion.
John Tlumacki/The Boston Globe via Getty Images
The second explosion goes off near the finish line.
The second explosion goes off near the finish line.
David L. Ryan/The Boston Globe via Getty Images
The first explosion knocked down<a href="http://piersmorgan.blogs.cnn.com/2013/04/15/bill-iffrig-subject-of-iconic-boston-globe-photo-the-shock-waves-hit-my-whole-body-my-legs-just-started-jittering-around-i-knew-i-was-going-down/"> 78-year-old runner Bill Iffrig</a> at the finish line. He got up a few minutes later and finished the race.
The first explosion knocked down 78-year-old runner Bill Iffrig at the finish line. He got up a few minutes later and finished the race.
John Tlumacki/The Boston Globe via Getty Images
A runner embraces another woman on the marathon route near Kenmore Square.
A runner embraces another woman on the marathon route near Kenmore Square.
Alex Trautwig/Getty Images
Former New England Patriots <a href="http://bleacherreport.com/articles/1606043-former-new-england-patriot-joe-andruzzi-assists-survivors-at-boston-marathon" target="_blank" target="_blank">offensive lineman Joe Andruzzi</a> carries a woman from the scene.
Former New England Patriots offensive lineman Joe Andruzzi carries a woman from the scene.
Bill Greene/The Boston Globe via Getty Images
A victim of the first explosion is helped on the sidewalk of Boylston Street.
A victim of the first explosion is helped on the sidewalk of Boylston Street.
John Tlumacki/The Boston Globe via Getty Images
An injured person is taken away from the scene in a wheelchair.
An injured person is taken away from the scene in a wheelchair.
David L. Ryan/The Boston Globe/Getty Images
A woman kneels and prays at near the finish line.
A woman kneels and prays at near the finish line.
John Tlumacki/The Boston Globe via Getty Images
People run down Exeter Street after the blasts.
People run down Exeter Street after the blasts.
Bill Greene/The Boston Globe via Getty Images
The explosions occurred around 2:45 p.m., about an hour after the first of the race's nearly 27,000 runners had crossed the finish line.
The explosions occurred around 2:45 p.m., about an hour after the first of the race's nearly 27,000 runners had crossed the finish line.
courtesy Dan Lampariello
Victims lie on the ground at the scene of the first explosion.
Victims lie on the ground at the scene of the first explosion.
John Tlumacki/The Boston Globe via Getty Images
A couple runs from the scene pushing a stroller.
A couple runs from the scene pushing a stroller.
Bill Greene/The Boston Globe via Getty Images
A runner reacts near Kenmore Square after the explosions.
A runner reacts near Kenmore Square after the explosions.
Alex Trautwig/Getty Images
A man's blood-stained feet hang outside an ambulance.
A man's blood-stained feet hang outside an ambulance.
Jim Rogash/Getty Images
A bystander who was injured in the first explosion is wheeled across the finish line while receiving medical attention from rescue workers.
A bystander who was injured in the first explosion is wheeled across the finish line while receiving medical attention from rescue workers.
John Tlumacki/The Boston Globe via Getty Images
<a href="http://www.cnn.com/2013/04/16/us/boston-heroes/index.html">Carlos Arredondo</a> was at the race handing out American flags to spectators. After the blasts, he helped emergency responders and is credited with helping a man survive serious leg wounds.
Carlos Arredondo was at the race handing out American flags to spectators. After the blasts, he helped emergency responders and is credited with helping a man survive serious leg wounds.
Darren McCollester/Getty Images
The second explosion goes off near the finish line.
The second explosion goes off near the finish line.
John Tlumacki/The Boston Globe/Getty Images
Police look at blown-out windows. The bombs shook buildings, witnesses said, sending people to seek shelter under tables.
Police look at blown-out windows. The bombs shook buildings, witnesses said, sending people to seek shelter under tables.
John Tlumacki/The Boston Globe via Getty Images
Unclaimed runners' bags fill an area near the marathon finish.
Unclaimed runners' bags fill an area near the marathon finish.
Kelvin Ma/Bloomberg via Getty Images
Women desperate to hear from loved ones are unable to get close to the site of the attack.
Women desperate to hear from loved ones are unable to get close to the site of the attack.
Bill Greene/The Boston Globe via Getty Images
Police and runners stand near Kenmore Square after the attack.
Police and runners stand near Kenmore Square after the attack.
Alex Trautwig/Getty Images
Runners gather near Kenmore Square after the explosions.
Runners gather near Kenmore Square after the explosions.
Alex Trautwig/Getty Images
An EMT worker is transferred to an ambulance outside a medical tent in Copley Square.
An EMT worker is transferred to an ambulance outside a medical tent in Copley Square.
John Blanding/The Boston Globe via Getty Images
A SWAT team arrives on the scene.
A SWAT team arrives on the scene.
Darren McCollester/Getty Images
A runner sits near Kenmore Square after the attack.
A runner sits near Kenmore Square after the attack.
Alex Trautwig/Getty Images
Runners who had not yet finished the race are stopped after the explosions.
Runners who had not yet finished the race are stopped after the explosions.
Yoon S. Byun/The Boston Globe via Getty Images)
Victims are helped at the scene of the first explosion.
Victims are helped at the scene of the first explosion.
John Tlumacki/The Boston Globe via Getty Images
A man in tears is helped at the scene on Boylston Street.
A man in tears is helped at the scene on Boylston Street.
Bill Greene/The Boston Globe via Getty Images
Passersby put pressure on a victim's leg to try to stop the bleeding.
Passersby put pressure on a victim's leg to try to stop the bleeding.
John Tlumacki/The Boston Globe via Getty Images
Massachusetts State Police guard an area near Kenmore Square.
Massachusetts State Police guard an area near Kenmore Square.
Alex Trautwig/Getty Images
Bystanders embrace near the finish line.
Bystanders embrace near the finish line.
CJ GUNTHER/EPA/LANDOV
Police officers gather on Newbury Street.
Police officers gather on Newbury Street.
Aram Boghosian for The Boston Globe via Getty Images
Women and children are escorted away from the scene.
Women and children are escorted away from the scene.
Bill Greene/The Boston Globe via Getty Images
Bomb squad officials check a possible suspicious device near the scene of the blasts.
Bomb squad officials check a possible suspicious device near the scene of the blasts.
SCOTT EISEN/Reuters/LANDOV
A woman is comforted after the blasts.
A woman is comforted after the blasts.
JESSICA RINALDI/reuters/LANDOV
Two injured women are taken away on stretchers.
Two injured women are taken away on stretchers.
David L. Ryan/The Boston Globe/Getty Images
An injured woman is loaded into an ambulance.
An injured woman is loaded into an ambulance.
Jim Rogash/Getty Images
First responders load injured people into an ambulance.
First responders load injured people into an ambulance.
Kelvin Ma/Bloomberg/Getty Images
An injured man is prepared to be moved from a stretcher to an ambulance.
An injured man is prepared to be moved from a stretcher to an ambulance.
Jim Rogash/Getty Images
An injured woman is placed on a stretcher.
An injured woman is placed on a stretcher.
David L. Ryan/The Boston Globe/Getty Images
A runner is comforted following the attack.
A runner is comforted following the attack.
Aram Boghosian for The Boston Globe via Getty Images
The Cambridge Police Department's bomb squad investigates unattended personal items left behind after the explosions.
The Cambridge Police Department's bomb squad investigates unattended personal items left behind after the explosions.
Barry Chin/The Boston Globe via Getty Images
Bystanders check their mobile devices for news of the explosions.
Bystanders check their mobile devices for news of the explosions.
Jim Davis/The Boston Globe via Getty Images
A member of the bomb squad investigates a suspicious item on the road near Kenmore Square.
A member of the bomb squad investigates a suspicious item on the road near Kenmore Square.
Alex Trautwig/Getty Images
A runner in a wheelchair is taken from a triage tent after the explosions went off.
A runner in a wheelchair is taken from a triage tent after the explosions went off.
JESSICA RINALDI/reuters/LANDOV
People comfort each near the site of the blasts.
People comfort each near the site of the blasts.
JESSICA RINALDI/reuters/LANDOV
Racers and race officials stand by after the explosions.
Racers and race officials stand by after the explosions.
NEAL HAMBERG/reuters/LANDOV
Emergency personnel respond to the scene.
Emergency personnel respond to the scene.
David L. Ryan/The Boston Globe/Getty Images
Police and emergency crews tend to victims.
Police and emergency crews tend to victims.
David L. Ryan/The Boston Globe/Getty Images
An injured woman is carried away on a stretcher.
An injured woman is carried away on a stretcher.
David L. Ryan/The Boston Globe via Getty Images
A man lies on the ground after the incident.
A man lies on the ground after the incident.
David L. Ryan/The Boston Globe via Getty Images
Officials watch as the first explosion goes off on Boylston Street.
Officials watch as the first explosion goes off on Boylston Street.
John Tlumacki/The Boston Globe via Getty Images
Spectators leave the bleachers after the explosions.
Spectators leave the bleachers after the explosions.
David L. Ryan/The Boston Globe via Getty Images
Police inspect one of the blast sites.
Police inspect one of the blast sites.
courtesy Bruce Mendelsohn