By Tori Mason

JEFFERSON COUNTY, Colo. (CBS4)– Earlier this month, a teenager fell 100 feet down an abandoned mine shaft and it took rescuers hours to reach him. He survived, thanks to the quick thinking of rescue crews.

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It was Dec. 7 when West Metro Fire responded to their 21st rescue call of the year in Golden.

(credit: CBS)

“We could hear some faint screaming, but we couldn’t discern the words. We knew he was alive,” recounted West Metro Fire Rescue firefighter Mike Brouillette.

West Metro Fire and several other agencies rushed to the large hole where the 15-year-old had fallen. He was about 100 feet below the surface.

(credit: CBS)

It wasn’t Mike Brouillette’s first rescue. He’s been saving lives for over 20 years. So, when he laid eyes on that mine shaft, he knew it wouldn’t be easy.

“There’s potential hazard of collapse, falling debris, unknown obstacles in your path and essentially an unknown route,” said Brouillette.

West Metro Fire Rescue firefighter Mike Brouillette (credit: CBS)

The teen was already 40 feet down when he fell another 60 into the mine shaft near Interstate 70 and West Colfax Avenue. To make matters worse, the hole did not go straight down.

“It was so far underneath ground. Once you get away from visible light, there are no sources of light other than what you carry,” explained Brouillette.

Copter4 was over the old mine shaft when rescue crews pulled the teen to safety. (credit: CBS)

During these type of rescues, crews usually use a type of stretcher called a stokes basket. The shape of their path made it impossible.

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Brouillette had to get creative.

“What I did was create a makeshift harness out of webbing. I was able to improvise and attach that harness I made for him onto my system. We pulled him out and raised him up on my back once I got into a vertical position,” explained Brouillette.

(credit: West Metro Fire)

The teen was alive, but the crews still weren’t home free.

“Once I got to him, my air monitoring device started alarming,” he explained.

The pair were able to make it up to fresh air just in time. Nearly four hours after he fell, Brouillette and his crew finally pulled out the injured teen.

(credit: CBS)

“I’m just happy that he and his family were able to spend the holidays together. That’s huge in my book,” said Brouillette.

The 15-year-old suffered a broken leg, but first responders say it could have been much worse.

(credit: West Metro Fire Rescue)

West Metro Fire told CBS4 that 2017 was an unusually high call volume year. The mine shaft rescue was their 21st for the year compared to most years where they have about a dozen rescues.

That mine shaft was previously covered but naturally opened up this past spring. Jefferson County Open Space told CBS4 they’re working with the state to get that repaired, so something like this doesn’t happen again.

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Tori Mason is an award-winning reporter for CBS4 This Morning. Follow her on Twitter @ToriMasonTV.