The Moment of Terror at the Boston Marathon

Runners and spectators describe the sheer horror and chaos when the blasts went off.
2:35 | 04/16/13

Coming up in the next {{countdown}} {{countdownlbl}}

Coming up next:

{{nextVideo.title}}

{{nextVideo.description}}

Skip to this video now

Now Playing:

{{currentVideo.title}}

More information on this video
Enhanced full screen
Explore related content
Comments
Related Extras
Related Videos
Video Transcript
Transcript for The Moment of Terror at the Boston Marathon
-- images of the city -- erupted half eaten sandwiches abandoned on the street where the bombs went off. As tonight ABC's Dan Harris -- new insight taking us behind those images we all watch together as a. Happened. Tonight new video is getting -- fresh frightening insight into the attacks. Look at this cell phone footage shot by a spectator standing between the two -- After the first explosion there's -- Relative comments people move away but then after eleven seconds -- by. -- second explosion can. In the aftermath you can see people running along sidewalks carpeted in glass and victim. And the thick -- -- Police scanner traffic makes this even further inside the -- I don't think -- tell them. There are other ways -- there -- under way. So many indelible images the face in the -- rose one of three members of the same family injured. And that 78. Year old runner who was knocked down but picked himself up and finish the race. Today. Boston -- and armored vehicles uniform national Guardsmen and officers armed with high powered rifles. On a normal Tuesday afternoon in this part of town will be crawling with foot and road traffic but today is basically locked down the police have created a massive crime scene. To give you an idea of the size of this thing take a look at the map we're standing on one corner of what is a twelve block crime scene. Right in the heart of this city. Also today we got our first HTT -- of those did not survive. Eight year old Martin Richard. And 29 year old crystal Campbell. Sprint doesn't dark. He can't believe that's -- it. Her mother said that. Her death was just a waste late today we learned. That the third victim was a graduate student at Boston University we do not have a name there and of course scores of other people were injured in in this attack the current total. Stands at 176. And Diane. They give you a sense of how Boston is coming together in the wake of these attacks late today the Red Cross announced that it is now turning away blood donors. They say they are simply. At capacity.

This transcript has been automatically generated and may not be 100% accurate.

{"id":18974005,"title":"The Moment of Terror at the Boston Marathon","duration":"2:35","description":"Runners and spectators describe the sheer horror and chaos when the blasts went off.","section":"WNT","mediaType":"Default"}