A pair of dedicated firefighters took to gym stairmasters to climb 110 floors while dressed in their full gear, in memory of the victims of the 9/11 terror attacks.
Decked out in their uniforms, helmets and with one even carrying an oxygen tank, the everyday heroes took step after step in a Planet Fitness in Bonaire, Georgia.
They climbed the same amount of staircases as their colleagues would have done back on September 11 in 2001.
This duo began their ascent at 8.46am yesterday, the moment American Airlines Flight 11 hit the north tower of the World Trade Center.
That was the first of the two aeroplanes to crash into the Twin Towers. Two further planes were hijacked, with one crashing into the Pentagon building, and another failing to reach its target, thanks to the efforts of the brave people on board.
The firefighters were paying tribute to the 3,000 people that were killed, 343 of which were staff from the fire service.
In less than 24 hours, the video has amassed more than 17 million views.
The woman who filmed the footage, who does not want to be named, said: "Two firefighters at my gym walked all 110 stories of the World Trade Center and back down in remembrance of 9/11 and to honour all the fallen heroes."
This isn't the first time firefighters have paid tribute to their fallen colleagues.
In 2016, Jason Harding was pictured at the gym in his firefighter uniform using the steps machine.
Lezlie Bauler, who works on the front desk at the gym in Tennessee, uploaded the image to Facebook saying: "This man asked if it was okay for him to climb 110 sets, fully suited, of stairs in honour of his fallen brothers and sisters for 9/11.
"Yes sir, you can. I am not one to get emotional, but a few tears were shed. Thank you for your services."
Credit: Facebook/Lezlie Bauler
Since being snapped, Harding, a public safety officer who works as a policeman, firefighter and paramedic, said: "When I went to the gym this morning at 6am before coming onto shift I was only wanting to honour the fallen heroes and their families on this day 15 years ago.
"I was not and am still not looking for any self-recognition. I have received so many private messages via Facebook from people expressing support, gratitude and blessings.
"Many stated my act brought them to tears but little do they know, their support did the same for me. It is proof that although we seem divided as a country at times, we unite at the most crucial times."
If these three firefighters don't define what it means to be a LAD, we don't know what ever will.
Featured Image Credit: Caters