Celina firefighter and paramedic Garrett Lane climbed 110 stories at the Comerica Bank Tower in Dallas on Sept. 5 to honor first responders killed in the Sept. 11, 2001, attacks.

Lane, 31, was in first grade when his father pulled him out of school as planes struck the World Trade Center. Star Local Media reported that Lane has made it his duty to keep the memory of that day alive, 25 years after the attacks.

He joined more than 400 firefighters, police officers and EMTs at the Dallas 9/11 Memorial Stair Climb, CBS Texas reported. The annual event honors the 343 firefighters, 70 law enforcement officers and nine EMS workers who died at the World Trade Center. According to the event's organizers, the climb is not a race and not a fundraiser. It is a remembrance.

Participants climbed in full gear. The Shorthorn reported that climbers ascended 49 floors, descended, climbed 12 more, descended again, then climbed another 49 floors. The Comerica Bank Tower stands 60 stories tall, so reaching 110 stories meant repeating sections of the building. Climbers wore photographs of individual first responders who died in the attacks and listened to radio transmissions from Sept. 11, 2001, as they ascended.

The National Fallen Firefighters Foundation said the 9/11 Memorial Stair Climb program began Sept. 11, 2005, when five Colorado firefighters climbed 110 flights in Denver in memory of fallen FDNY members.

Rodney Smith, operations coordinator for the Dallas 9/11 Memorial Stair Climb, told CBS Texas at the Sept. 5 event that the climb also connects younger first responders to the history of that day. "A lot of our firefighters over the last couple of years weren't born then, so it's our opportunity also to share our experience," Smith said.

First responders from Texas, Oklahoma, New Mexico and New York participated. The event began with a remembrance ceremony at Main Street Garden Park in Dallas, where bells tolled before participants walked to the tower.

The City of Celina scheduled its own 9/11 Anniversary Ceremony for Sept. 11 at the Downtown Square from 8 to 9 a.m.