The tragedy — which has left two dead and more than 100 injured — was captured on video by dozens of onlookers. Watch one of the most harrowing views below.
The Boston Marathon bombing tragedy has shaken the world, and the shocking video of the blasts has to be seen to be believed.
2013 Boston Marathon Video — Footage Of The Horrific Attack
The video of the April 15 tragedy fully shows the power of the massive explosion, which shook the street and surrounding buildings — leaving many injured and at least two dead.
Boston Marathon Tragedy: One Eyewitness Speaks Out
Jeff Chin, a 27-year-old eyewitness of the blast, described the mayhem to PEOPLE.
I saw a woman fall down as she was running away; she was trying to get up and people were stepping all over her, trampling her. She was screaming in pain, but also I think she was terrified.
She was trying to get up, and I saw a guy step right on her hand and she screamed out. I was going over to help her, and then another woman helped her get on her feet.
There was a woman carrying a girl who was maybe 8 years old, way too big to be carried. The girl was screaming, I’ll never forget how it sounded. She was screaming, not any words, but just shrieking and kicking and flailing. And I saw that there was blood, but I don’t know if it was the mother or the girl. The girl was just terrified.
Our thoughts and prayers go out to the victims and their families.
— William Earl