9/11 Heros Run remembers first responders who lost their lives in 9/11

Runners, walkers and ruckers — walkers and runners carrying weighted rucksacks or backpacks — took to the starting line at Great Lawn Park in Denver Sunday morning to participate in the 9/11 Heroes Run.

The 5K event, sponsored by the Travis Manion Foundation, welcomed people of all ages to "honor the heroes of September 11th and those who've served our nation since," according to the foundation's website.

"Well, Travis Manion, First Lieutenant of the United States Marine Corps, made the ultimate sacrifice in April of 2007 when he — three separate times — took fire upon himself to get his teammates into a position where they could get out of an ambush and honoring that sacrifice that he made," Kassidy Childers, a staff member with the foundation, said.

Among the ruckers Sunday was former Marine Matthew Sanchez.

"I always think of everybody that we've lost, you know, whether it's to suicide or it's to just passing away during during war and whatnot," he said. "Rucking is kind of a way for me to say, 'Hey, I got it, you know, I'm carrying this weight. I'm carrying everything forward.'"

Along the route, others carried weight too. One man was in a full firefighter uniform, and another in a 100-pound bomb suit — all of them simulating the physical and emotional response of those who hiked stair after stair in full uniform to save those trapped in the twin towers.

"I think it is extremely impactful. I come from a military family. My cousin deployed shortly after 9/11 and he was with Marines. My dad was in the Marine Corps as well," Sanchez said.

The foundation created the event in 2008, and it's now in more than 50 cities across the nation, including Denver.

"I think, like most Americans, we who were alive during the time, we all remember where we were on 911," Childers said. "To have a community to come out and support and keep that promise that promise that we made to our first responder community, that we would never forget those attacks that happened on 9/11 and how they shaped our nation and the future generations."