Transcript for Heart-Stopping Moment at a High School Gym
Finally, sometimes timing is everything. At a high school in Utah, faculty that had recently completed a cpr refresher course were put to the test when a student collapsed. This was no drill. And as the surveillance video you're about to see showed, they had just seconds to react. Here's Linzie Janis. Reporter: Watch these middle schoolers jogging in gym class, when suddenly 14-year-old Skyler Nelson slows down, puts his hands on his hips, then collapses onto the floor. Surveillance cameras rolling as the teacher checks his pulse and calls for help. He was trying to breathe at first. Then there was a point where he stopped breathing altogether. Reporter: Vice principal Eric price, who attended a cpr refresher course just days earlier, putting his knowledge into action. Price and the school resource officer alternating applying compressions. He had actually, essentially, died right there in our gym. He wasn't with us. He was gone. He was gone. Reporter: 11 terrifying minutes later, paramedics arriving, rushing Skyler to the hospital where doctors discovered a genetic heart defect, implanting a defibrillator in his chest. I'd like to say thank you very much, I'm grateful, and god bless you. Reporter: Skylar's heroes visiting him in the hospital. Skylar looked at us as we were leaving and said, "Thank you for saving my life." Reporter: Tonight, grateful they'd brushed up on their life saving skills. Linzie Janis, ABC news, new York. So great they had that training. "Gma" first thing in the morning.
This transcript has been automatically generated and may not be 100% accurate.