LOS ANGELES » Extreme athlete Dean Potter knew the risks every time he flew off a cliff with a parachute.

He lost a friend to a BASE jumping accident last year and spoke about the death-defying nature of the sport at that friend’s memorial service.

“He always recognized how dangerous the sport was and at the same time, how magical it was — the tension between those two things,” fellow climber Chris McNamara said.

Potter, renowned for his daring and sometimes rogue climbs and BASE jumps, was one of two men killed after jumping from a 7,500-foot promontory in Yosemite National Park.

Someone called for help late Saturday after losing contact with Potter, 43, and his climbing partner, Graham Hunt, 29.

Park ranger Scott Gediman said rescuers looked for the men overnight but couldn’t find them. On Sunday morning, a helicopter crew spotted their bodies in Yosemite Valley.

The men wore wing suits — skintight suits with batwing sleeves and a flap between their legs — to help them glide. However, parachutes designed to slow their descent had not been deployed, Gediman said.

BASE jumping, in which people parachute from a structure or cliff, is illegal in all national parks. It’s possible the men jumped at dusk or at night to avoid being caught.

“BASE jumping is the most dangerous thing you can do … every time you jump it’s a roll of the dice,” said Corey Rich, a photographer who documented some of Potter’s feats. “The odds are not in your favor, and sadly, Dean pulled the unlucky card.”

Potter and Hunt, who lived near Yosemite, were prominent figures in the park’s climbing community, Gediman said.

“This is a horrible incident, and our deepest sympathies go out to their friends and family,” Gediman said. “This is a huge loss for all of us.”

Potter is famous for pushing the boundaries of climbing by going up some of the world’s most daunting walls and cliffs alone, using his bare hands and without ropes. He took the sport to an extreme level with highlining — walking across a rope suspended between towering rock formations while wearing a parachute for safety in case of a fall.

He drew criticism in May 2006 after he made a free solo climb of Utah’s iconic Delicate Arch in Arches National Park. Though it was not illegal, outdoor clothing company Patagonia stopped sponsoring him, saying his actions “compromised access to wild places and generated an inordinate amount of negativity in the climbing community and beyond.”

Potter defended his ascent, saying his intention was to inspire people to “get out of their cars and experience the wild with all their senses.”

Clif Bar withdrew its sponsorship of Potter and four other top climbers last year, saying they took risks that made the company too uncomfortable to continue financial support.

In recent years, Potter combined his love of climbing and flying with BASE jumping. He produced a film that chronicled his adventures BASE jumping with his beloved dog, Whisper.

In 2009, he set a record for completing the longest BASE jump from the Eiger North Face in Switzerland by staying in flight in a wingsuit for 2 minutes and 50 seconds. The feat earned him the Adventurer of the Year title by National Geographic magazine.

Potter indicated in his writings that he knew the inherent danger of the sport. Last March, his friend and climbing partner Sean “Stanley” Leary died in Zion National Park in Utah after apparently clipping a rock outcropping during a BASE jump. Potter was among a group of people who recovered Leary’s body.

“Though sometimes I have felt like I’m above it all and away from any harm, I want people to realize how powerful climbing, extreme sports or any other death-consequence pursuits are,” he wrote in an October 2014 blog post on his website. “There is nothing fake about it whether you see it in real life, on YouTube or in a glamorous commercial.”

Gediman estimates that about five BASE jumping deaths have occurred in Yosemite. He said he watched a BASE jumper leap to her death in 1999 when her chute failed to open.