There is a place deep in the canyonlands of western Colorado, high on a rugged plateau that stretches to the Utah border, that only the locals know about.
In this place, frigid mountain streams have carved out a playground of waterfalls and pools to swim in. It's called the Potholes, for the many deep pools created over millennia by the pounding current.
Only the bravest -- or most foolish -- dare to jump from the high cliffs into the water. Jumpers must clear jutting ledges to hit the deep pockets of water.
There have been accidents here. And there will be more.
"Three hundred days out of the year it could be the safest place in the entire world," said Aaron Ingels, now 23, who made a fateful trip with friends to the Potholes just over a year ago. "But on that very day ... it's not a safe place."
Watch the full story Friday on "20/20" at 10 p.m. ET
Click HERE for photos of Stevie Burns and friends at the Potholes.
Ingels and his friends still have a picture, and home video, from that day -- May 31, 2008. In one image, the friends stand around a sign that warns swimmers about dangerous waters.
What did the sign mean to them that day?
"Nothing," Ingels said.
"20/20" recently accompanied five young people from the Denver area on a return trip to the Potholes, where they marked the moment their lives changed forever ... when six good friends became five.
"It's just hard being back here and telling the story again," Kristen Kroonenberg said.
The fateful trip came during the height of the spring runoff. Snowmelt from the mountains poured down the canyons, ice cold and deadly fast.
The friends recorded a home video of roaring, rushing water.
"That hole down there was a complete boiling pot of water," said Ingels, pointing into the maelstrom. "Not a single bit of calm water in it. I had the fear of death of me when I saw that hole."
But the fear isn't readily apparent on video the youths shot that day. "First day at the Potholes," one of them, Stevie Burns, 19, said. "You know, ain't no thang."
"It was really, really loud," Kroonenberg, now 20, remembered. "It was rushing pretty hard. I just had a bad feeling about it."
But who listens to a bad feeling when the sun's warm and your friends are calling.
Burns was the first to jump.
"He came up next to us," Kroonenberg said. "We thought he was just looking down like we were. And then all of a sudden he just jumps in."
"Stevie [Burns] jumped in that hole and got out so effortlessly that I just thought everything was fine," Ingels said.
For the time being, everything was fine. Then Burns decided to jump again, this time from the highest ledge.
Now the camera shows fear creeping in.
"He walked up to the 65-foot ledge and he was trying to get himself to jump off," Kroonenberg said.
For eight minutes, Burns stood 65 feet above the raging water, before finally backing down.
But on a ledge just below him, Kroonenberg had worked up the courage to jump. She recalled "falling down there and going into the water."
"I went pretty far down," she said.
And that, Ingels said, is when the nightmare began.
"The moment she resurfaced, I knew she wasn't going to make it out," he said. "Just the terrified look on her face."
Kroonenberg said, "I didn't think anybody could see me. I didn't think anybody was watching because I couldn't hear anybody. I had a hard time. I couldn't move."