DULUTH, MN -- The deadliest attack in the country's history still remains at the forefront of first responder's minds.
"It's an event that will never be forgotten," said Deputy Chief Duluth Fire Department, Scott Kleive.
The numbers engraved in their minds.
"There are 343 firefighters that died that day as well as 60 police officers and 8 paramedics and over 3,000 civilians,' said Duluth Firefighter, Andrew Olson.
"Those were our brothers and sisters that lost their lives that day."
Olson said being a first responder is more than a job, it's an identity, "I go home and I am a firefighter to my kids, my family, even though I may not be wearing a uniform I still am a firefighter everywhere I go."
Which is why he chose to start a memorial stair climb two years ago, to honor the fallen women and men of 9/11.
Friday morning, Firefighters climbed more than 2,000 steps, fully dressed in response gear, along with an oxygen tank, just as those who responded on that somber day.
"We'll have ten firefighters climbing 110 stories on the stairs from the upper and lower bowls of the Amsoil arena," said Olson.
Step by step, carrying an extra 40 pounds.
Fighting through the pain, while remembering those who fought for them.
"Take a moment and hug your loved ones and tell those close to you how important they are because tomorrow is never guaranteed," said Olson.
All money raised at the memorial stair climb will be donated to the I-A-F-F Fallen Firefighters Memorial Fund.
To donate click here.