It was a gory ending of the Boston Marathon, the oldest marathon in the world since 1897, when two powerful blasts one after the other near the finish line left two dead and at least 120 injured.
Two blasts ripped through the spectator area near the finish line and it is suspected that the explosive devices contained ball bearings.
There has been no immediate claim of responsibility. Reports emerged later that one of the dead was an eight-year-old boy and the youngest injured is believed to be three years old.
According to initial reports, at least ten injured require amputations.
Roupen Bastajian, a 35-year-old state trooper from Rhode Island, had just finished the race when they put the heat blanket wrap on him and he heard the first blast.
'I started running toward the blast. And there were people all over the floor,' he said. 'We started grabbing tourniquets and started tying legs. A lot of people amputated. At least 25 to 30 people have at least one leg missing, or an ankle missing, or two legs missing.'
A Boston police officer was wheeled from the course with a leg injury that was bleeding.
'There are a lot of people down,' said one man, whose bib No 17528 identified him as Frank Deruyter of North Carolina. He was not injured, but marathon workers were carrying one woman, who did not appear to be a runner, to the medical area as blood gushed from her leg.
Watch the video of the blast (beware of graphic contenet)