Eyewitnesses at the Boston Marathon described the ground shaking beneath their feet, smoke and "a lot of chaos" this afternoon when explosions killed three people and injured more than 130.
Rachel Sibley, 22, was 50 feet from the finish line waiting for a friend to cross.
WATCH: Marathon Witness
"All of a sudden I heard this bang that sounded like a cannon," she said. "You could see people looking up at the sky like there were fireworks, like a celebratory bang. The whole...Full Story