Spencer Butler and Grant Krause were returning from a rock climbing excursion with their new GoPro camera Saturday when they saw smoke billowing out of a building at the Stoney Creek Highland apartment complex.
The men, both in the Air Force, stopped in hopes of getting some shots of Rapid City firefighters in action. Their plan changed quickly, however, when the two realized the fire department had not yet arrived.
"You guys know of anybody in the building?" Butler said to residents standing outside, on the video. "Did you knock on all the doors? ... Dude, should we just bang on doors anyways? All right."
With his camera rolling, Butler, along with Krause and a few others, banged on doors and then knocked them down looking for residents and animals.
"It was pretty awesome to have complete strangers get involved like that," Butler told ABC News. "We just started ramming into the door, burst it open, ran inside and asked if anybody was inside and needed help. ... We all really knew what we had to do and just did it."
Within minutes, though, the smoke had overwhelmed the two men.
"Let's get the h--- out of here," said Butler, as his camera captured firefighters dousing the flames pouring out of the roof of a building.
Rapid City firefighters said the fire resulted in a partial roof collapse and that one person was hospitalized for smoke inhalation.
"I'm sure anybody else would do the same thing," Butler told ABC News. "You just kind of make the decision to actually act and once you start doing it, it's just all instinct. ... My hopes out of this all is that it will encourage people to not just be a bystander and act when they see something like this happen."