Boston marathon blasts kill 3 and injure more than 100

Two powerful bombs exploded near the finish line of the Boston Marathon on Monday afternoon, killing three people, including a child, and injuring more than 100, as one of this city's most cherished rites of spring was transformed from a scene of cheers and sweaty triumph to one of screams, bloody carnage and death. (Video courtesy: ABC News, Al Jazeera)