We're going to turn to the dramatic video of a so-called glacier slide that goes terribly wrong. What was supposed to be fun turns dangerous. You hear the two young men falling under a glacier. All of... See More
We're going to turn to the dramatic video of a so-called glacier slide that goes terribly wrong. What was supposed to be fun turns dangerous. You hear the two young men falling under a glacier. All of it caught on camera. And ABC's Neal Karlinsky has the pictures. Reporter: 21-year-old Devon Fister, living a moment of crisis with a gopro camera on him, atop a steep glaser in Utah. Down below, his long-time friend, Randall Reese, bodily hurt while sliding down on his back. When suddenly, watch closely. Stop yourself,boro. . Reporter: His friend, Aaron, slides out of control, too, tumbling after going over a 15-foot cliff. Are you okay? Call an ambulance. Reporter: Spread out across the glacier, now two are badly hurt. When Devon reaches Randall down below, he seems dazed. What did you hit? Reporter: Devon gives him the t-shirt off his back to keep warm. Call the medevac. And a friend over the cliff? Yeah. There's like a thing of snow. And he slid down the snow. And he couldn't stop. Reporter: Along with three other friends, the three men made what now seems the incredibly foolish choice to slide down this steep, snowy cliff last week, figuring it would be a fun, fast ride. Good times. Reporter: The first few runs went fine. Just barely. That is not safe. I was definitely scared. I didn't think I was going to stop. So, it's pretty frightening. Reporter: Randall broke his speak bone and needed 25 stitches to his face and ankle. Aaron was banged up with a sprained ankle but nothing broken. They were eventually rescued by a climbing team and helicopter, after spending most of the night on the mountain. Devon by their side, the whole time. I think if he wouldn't have been there, things would have been a lot different. Reporter: For "Good morning America," Neal Karlinsky, ABC news, Seattle. We're glad the whole thing ended well. Nobody, try that at home. Very true.
This transcript has been automatically generated and may not be 100% accurate.