An unidentified runner leaves the marathon course, crying, near Copley Square following the explosion.
Winslow Townson/AP
Police officers with their guns drawn hear a second explosion down the street near the finish line of the Boston Marathon. The first explosion knocked down a runner at the finish line. At least two people died and dozens were injured in the Monday blasts.
John Tlumacki/Boston Globe via Getty Images
President Obama is updated on the Boston explosions by FBI Director Robert Mueller. Seated with the president are Lisa Monaco, assistant to the president for homeland security and counterterrorism, and Chief of Staff Denis McDonough.
Pete Souza/The White House via Getty Images
One of the blast sites on Boylston Street, near the finish line of the Boston Marathon, is investigated by two people in protective suits.
Elise Amendola/AP
Runners gather near Kenmore Square, about a mile away from the finish line, after two bombs exploded during the Boston Marathon.
Alex Trautwig/Getty Images
A policeman secures the area in front of the White House in Washington, D.C., after blasts in Boston. The block around the White House has been temporarily closed to pedestrians.
Mladen Antonov/AFP/Getty Images
A woman looks on as runners pass near Kenmore Square. Boston Police Commissioner Ed Davis says no other unexploded devices have been found.
Alex Trautwig/Getty Images
A Boston police officer wheels an injured boy down Boylston Street as medical workers carry an injured runner.
Charles Krupa/AP
Medical workers aid injured people at the finish line. The cause of the explosions has not been determined.
Charles Krupa/AP
A Boston police officer clears Boylston Street following the explosions.
Charles Krupa/AP
A man and a woman comfort each other near a triage tent.
