Mr. Crouch engaged the cornice. It snapped. He fell out of sight.
“Avalanche, avalanche!” shouted Cam Fitzpatrick, a fellow snowboarder, who had been standing nearer to Mr. Crouch than the others. The group swung into action, setting off a mountainside rescue that had to be accomplished within minutes to beat the odds of death from trauma or suffocation.
Mr. Crouch did not die. He was released on Friday from Vancouver General Hospital in Vancouver, British Columbia, after being treated for broken vertebrae, a torn pancreas and other injuries. Nature had just taught him that extreme sports can quickly turn from thrill to peril.
Mr. Crouch said on Instagram that the cornice “pulled me backward into a slide.”
“It took me through about 1,000 feet and over several rock bands before I ended up at the bottom, buried with no oxygen for almost 5 minutes,” he wrote, thanking the group for saving him.
The online community of board sports, both snow and surf, showed camaraderie. “Pray for Gold Medal U.S.A. Surf Team member and professional snowboarder, Brock Crouch!” U.S.A. Surfing, the sports governing body, wrote.
Mr. Crouch, who has also competed in International Ski Federation snowboard events, and the others were in the Pemberton Ice Cap region of British Columbia to work with Absinthe Films, which makes snowboarding films.
Weeks before they arrived, there had been an avalanche with a fatality in the region, and on Friday Shin Campos, a safety coordinator with Whistler Creek Productions in Canada, which was working with the group, said the group was aware. He said they carefully assessed the risks, such as taking into account temperature and winds, which can whip up snow and move it around to create destabilized patches that have not bonded.
The group surveyed the mountains from a helicopter, chose their routes and then set down the aircraft to plan descents. “Most people look at these guys and say, ‘They just hike up and snowboard down,” he said. “It is much more involved.”
John Jackson, 34, a professional backcountry rider from Nevada, said the group had airbags, shovels and other equipment.
When Mr. Crouch dropped out of sight, they switched their radios to search mode. Mr. Campos flagged the pilot, who started up the helicopter.
The riders knew they had to give chase, but first they had to navigate a safe route, cutting across debris and other hazards without putting themselves in danger or dropping more snow on the area where Mr. Crouch might be buried.
With the help of the pilot, they maneuvered to the bottom where the avalanche had stalled, hoping Mr. Crouch had ended up that far. “When we were going down, in the back of our mind you are thinking, ‘Wow we might be pulling out our dead friend,’” Mr. Jackson said.
The pilot spied something in the mound — the tip of a snowboard. Hopes rose, but avalanches are so violent that they can rip away equipment — a glove, a pole, a backpack.
It was around 2:15 p.m. The temperature, at 6,500 feet above sea level, was about 50 degrees Fahrenheit, as Mr. Jackson recalled. The men started to dig through packed snow.
Within minutes, Mr. Jackson said, they exposed a boot, and then tried to gauge where Mr. Crouch’s head might be. As the snow was cleared, he was found folded up, his head near his feet, Mr. Jackson said.
“He was taco’ed,” he said. “Because he was not directly upside down, his head was only two feet under the snow.”
The bluish tint vanished from his face as they cleared snow from his airway. He moaned. They extracted his body, supporting his neck and back. Mr. Crouch was responsive, biting Mr. Jackson’s fingers.
He had been buried for about five minutes. He had told his friends of trying to create an air pocket with his arms.
“That is incredibly rare you have this success story,” Mr. Campos said. “The chance of survival goes down rapidly after two minutes.”
In the hospital, Mr. Crouch shared photographs of his battered face. “I love snowboarding more today than I ever have and I can’t wait to get back on my board and shred with everyone again!” he wrote.