RED ROCKS, Colo. (KDVR) — Firefighters and community members gathered at Red Rocks Amphitheatre on Wednesday to walk the stairs in honor of the firefighters lost on Sept. 11, 2001.

The event has been hosted at Red Rocks for 15 years. Participants start at the south ramp and walk up the stairs and around the amphitheater nine times — the equivalent of the 110 floors of the Twin Towers.

According to the event’s website, on Sept. 11 at 8:46 a.m., walkers will gather together at the starting point, at 8:46 a.m. EST, the first plane hit the north tower.

From there, the event coordinators will give a brief speech about the event and the route. There will also be a moment of silence.

At 9:02 a.m., the time when the south tower was hit by a second plane, the Colorado Emerald Society Pipes and Drum Band will play Amazing Grace and the climb begins.

“The downtown stair climb registered 343 participants in less than seven days. Firefighters from five different states, representing 45 fire departments signed up. The waitlist swelled to over 200, including several dozen West Metro Firefighters. It was quickly realized there was a need to expand this great tradition and fitting tribute. On Aug. 6, with just over one month until Sept. 11, West Metro Firefighters Local 1309 approved a motion to establish and sponsor a separate memorial stair climb event.”

There is still time to register or donate to the climb.