BOSTON -- An onlooker captured the drama that followed the second blast near the finish line of the Boston Marathon on Monday.
The person who recorded it posted it on YouTube, stating they were right across from where the first bomb went off.
"Our hearts and prayers go out to the families and victims of today's tragedy," the photographer wrote.
Three people were killed in the blasts, including an eight-year-old boy. Nearly 150 other people were injured.
President Obama has pledged a full investigation into what happened.