Dean Potter – one of America’s best known extreme athletes – has been killed during a stunt in California.
The 43-year-old died while attempting a wingsuit flight from the 7,500 ft (2,286m) Taft Point promontory in Yosemite National Park, a park spokesman said.
Graham Hunt also died when their attempt to fly at high speed through a narrow gap in the skyline went wrong.
Rescuers found the bodies soon after contact had been lost with the men.
No parachutes had been deployed, reports say.
Extreme sport pioneer
The world of extreme sport has paid tribute to a climber that continuously pushed the limits of what was possible, sometimes controversially.
He was the first to climb Yosemite’s three most famous big walls in a single day.
He was also renowned for his high-line walks and high-risk parachute jumps, some of which he carried out with his dog, Whisper.
Last year he released a 22-minute long film, “When Dogs Fly” that chronicled Whisper’s skydiving adventures. Although it became a viral sensation, it also attracted criticism from animal rights activists.
Climber Doug Robinson said that Potter had always sought to push the limits of what was possible in his sport. “We’re very sad about Dean Potter’s death, but not very surprised,” he was pushing the envelope all his life.”
Dean Potter: The sensation of high-line walking
My vision turns black and white except for the searing red line.
Sounds fade. I feel faint, face flushed with heat.
My muscles tense, but I hold calmness in my centre and loosen my arms from the shoulders to my fingertips.
The moment sickens me, and my mind tries to stop it, but I command myself to walk.