More than 30 Austin firefighters climbed up and down the concrete stairs of the Pleasant Valley Drill Tower Sunday morning to remember their fallen colleagues in the Sept. 11 attacks.

All of them wore their yellow fighting fire gear. Most carried hoses and wore air tanks on their backs while they walked in complete silence.

"Just remember what happened that day. Just think about the lives that were lost and we will never forget those people that gave their lives for us," said Christopher Ruiz, a cadet.

Firefighters climbed up and down the stairs until they matched the 108 floors of the World Trade Center. One even carried his young son. Cold towels waited for them at each descent while school kids handed out cups of water.

"So we can remember the people who died," said 11-year-old, Natalie Smith, who is in the sixth grade.

The names of the 343 fallen firefighters were taped to the doors of the tower next to flower wreaths.

The Austin Fire Department sent ten firefighters to New York City to help in the days following the attacks.

"It's our way to remember the sacrifice they made also to renew our promise as first responders and firefighters to continue to protect the citizens of Austin," said AFD Division Chief, Palmer Buck.

The AFD Memorial Stair Climb started in 2001 when 343 NYFD firefighters lost their lives after the terrorist attacks; Much more have since passed away. The annual tradition is now the longest running in the country.

While it was hot and strenuous, the firefighters didn't mind because they were making the climb their FDNY brothers and sisters weren't able to make.