At 17 years old, he was paralyzed from the waist down. 3 years later, he competed in a marathon.

Mason Branstrator has always been an athlete, but three years ago, at just 17 years old, his active lifestyle changed forever.

"I was going for an ordinary day of downhill skiing, but this time, it was a lot different," Mason, an experienced skier who frequented the slopes in his home state of Minnesota, told CBS News. "I remember thinking right as I left the jump, 'I'm going a little fast.' And that was the last thing I remember before everything went black."

Mason broke his T-12 vertebra, which affects lower body functions. He was paralyzed from the waist down. As an avid runner, soccer player and skier, he couldn't wrap his mind around the fact he may never walk again.