Kyle Smaine, an American freestyle skier who was a halfpipe gold medalist at the 2015 world championships, was one of two men killed Sunday in an avalanche while backcountry skiing in Japan.

Smaine, a 31-year-old from South Lake Tahoe, Calif., was on a marketing trip for Ikon Pass and Nagano Tourism, according to the outdoor sports publication Mountain Gazette, and was in Japan for the "unbelievable snow quality," he had written on Instagram. Alterra Mountain Co., which owns Ikon Pass, confirmed Smaine's death in an email to The Washington Post on Monday and said it had occurred during downtime after his marketing duties had ended.

"We are deeply saddened by the loss of athlete and friend Kyle Smaine. He will be very missed among the Tahoe community and by his fans around the world," the company wrote. "Our thoughts and condolences go out to his family and extensive community of friends."

Earlier Monday, a spokesperson from the State Department confirmed in an emailed statement that a U.S. citizen was killed but would not confirm that person's identity, citing privacy concerns.

"The U.S. Department of State has no higher priority than the safety and security of U.S. citizens overseas," the statement read. "We are aware of an avalanche in Nagano, Japan on January 29. We can confirm the death of a U.S. citizen in Nagano on January 30. Due to privacy considerations, we have no additional details at this time."

A spokesperson at the U.S. Embassy in Tokyo said it was "aware of the incident in Nagano Prefecture and has been in touch with the relevant authorities to provide all appropriate assistance."

At least five skiers from the United States and Austria were caught in the avalanche on the eastern slope of Mount Hakuba Norikura, a Nagano Prefecture police spokesperson told Reuters. Three were able to escape the avalanche, but two skiers were found dead. Weather forced a search to be suspended, and their bodies were recovered Monday.

An avalanche warning had been issued for the area, with Japan dealing with widespread heavy snow and record cold. Backcountry skiing is popular among advanced skiers and snowboarders, lured by fresh, deep snow and the absence of crowds. "This," Smaine had written on Instagram along with video of him skiing, "is what brings me back to Japan each winter."

But even an experienced skier or snowboarder can trigger or be caught by a naturally occurring avalanche, which starts a race against the clock — and the odds — for rescue teams. Although most victims are buried by an average of only three feet of snow, the prospects for survival become increasingly unlikely after about 15 minutes, Dale Atkins, a past president of the American Avalanche Association and a former forecaster with the Colorado Avalanche Information Center, told The Post in 2021. When the avalanche stops, the snow compacts around victims, becoming almost like concrete.

Grant Gunderson, a Mountain Gazette photographer, and Adam Ü, a professional skier from Glacier, Wash., also were on the trip, and Ü told the Mountain Gazette that Smaine and the other deceased skier, who has not been identified, were transitioning their backcountry gear into uphill mode when the avalanche occurred.

"It was the last run of the last day of our trip," Ü told the publication.

As news of the tragedy swept through the freestyle skiing community, there were several remembrances on social media. Joss Christensen, a Park City, Utah, freestyle skier, replied to Smaine's most recent video: "Wish we had more time to ski these past few years. Thanks for always being such a positive energy Kyle."

The U.S. Free Ski Team wrote on Instagram that it had lost "an incredible person, friend, skier and teammate to the mountains," describing Smaine as "a fierce competitor but an even better person and friend."

Travis Ganong, an Olympian and freestyle skier, wrote that he was "heartbroken to hear of the passing of my friend. … He loved skiing more than anyone I knew, you will be missed."

Mio Inuma reported from Tokyo.