Monday footage of the Boston Marathon attack was seen around the world, and for some Coloradans it was seen far too close.
According to the Boston Marathon database, 521 Coloradans were enlisted to run the world's oldest annual marathon which soon became a chilling scene of terror when two bombs were detonated, killing three and wounding over 180.
For many it was a close call.
Nancy Antos, 63, told The Denver Post that she was running late for her wave and, had she been on time, she would have been at the scene of the explosion.
"It was like that movie 'Forrest Gump.' Everyone just stopped," Antos said. "Then it hit me, 'I would have been right in there if I was on schedule.' It was total chaos. I just lost it. I was just crying. I just became sick."
The Twitter account for the local Runners Roost began the day tweeting encouragement for Colorado runners and ended tweeting updates about runners and news about the explosions.
On Tuesday, the running store announced a special RunClub honoring the victims and asked participants to wear their past Boston Marathon gear.
George Schemel, 52, told The Colorado Springs Gazette the event sounded like cannons.
“It was incredible. It was crazy,” he said. “I’m very lucky. I missed it by only five minutes.”
Officials are reportedly already making plans to beef up security for the Bolder Boulder Memorial Day race.