Scenes From the Boston Marathon Bombing

Four hours, nine minutes and 43 seconds into the race, the first explosion rocked runners and spectators at the finish line of the 117th-annual Boston Marathon. Then 12 seconds later, a second explosion erupted. The jubilation of completing a grueling 26.2-mile race turned to chaos and terror. Here are some scenes from the catastrophe, one of the nation's worst attacks since Sept. 11, 2001.

By CNBC.com
Posted 16 April 2013

Marathon runners slow down as they see the first bomb detonate near the finish line.

A view of the bombs that went off at the finish line of the 117th Boston Marathon.

Police officers with their guns drawn hear the second explosion down the street.

First responders on the scene of the Boston Marathon bombing.

A wounded person is wheeled away on a stretcher.

The scene after first responders carried bomb victims away.

A runner fights back tears near Kenmore Square.

A SWAT unit arrives at the corner of Stuart Street and Dartmouth Street.

Police look at blown out windows at the scene of the first explosion on Boylston Street.

Pushing a stroller, a couple runs from scene on Exeter Street.

A bomb squad sapper inspects suspicious item near Kenmore Square

President Barack Obama talks on the phone with FBI Director Robert Mueller to receive an update.

A man displaying a flag leaves the scene near the finish line.

A woman kneels and prays at the scene of the first explosion.

Boston Marathon bomb scene pictures taken by investigators show the remains of an explosive device.

Boston Marathon bomb scene pictures taken by investigators show the remains of an explosive device.

Boston Marathon bomb scene pictures taken by investigators show the remains of an explosive device.

A view of the battery that was attached to the explosive device.

Inspectors reveal possible evidence left behind after the Boston Marathon explosion.

A close-up of the batter used in the explosive device.

Investigators continue to search the area for more explosive devices.

FBI and investigators continue to search the area for more bomb devices following the Boston Marathon bombings.

An FBI crime scene investigator places an evidence marker on Boylston Street just past Berkeley Street near the scene of the Boston Marathon bombing.

US military Humvees rolling down a deserted Boylston Street, which is considered a crime scene after two explosions rocked the Boston Marathon on Monday.

Flowers and a sign are left on a street post in Medford Square in remembrance of Krystle Campbell, 29, of Medford, Massachusetts, who was killed by the bomb explosions at the Boston Marathon.

A woman looks at a street memorial near the scene of twin bombings