A 41-year-old aerospace engineer and alpine climber died after falling approximately 3,000 feet from Mount McKinley in Alaska’s Denali National Park on June 2, marking the first climbing fatality of the 2025 season on North America’s tallest peak.
Alex Chiu of Seattle, Washington, was ski mountaineering along the West Buttress route with two climbing partners when he fell from an area known as Squirrel Point toward the Peters Glacier. The National Park Service reported that Chiu was climbing without rope assistance at the time of the accident.
The two other climbers witnessed Chiu’s fall onto the rocky, ice-covered face below. They attempted to lower themselves over the edge as far as possible but could not see or hear him after the fall, according to park officials. The climbing party then descended the route to seek help at Camp 1, located approximately 7,800 feet up the mountain.
Weather conditions prevented immediate rescue efforts. High winds and snow made both ground and air searches impossible until June 4. Two mountaineering rangers departed from Talkeetna, a village south of the mountain, conducting a helicopter search when conditions cleared on Wednesday morning.
Rangers successfully located and recovered Chiu’s body, which was subsequently transferred to the Alaska state medical examiner for official determination of the cause of death. The recovery operation concluded two days after the initial fall occurred.
Chiu worked as an aviation engineer for the Federal Aviation Administration and previously served as a software engineer at Boeing. He was an active member of the Seattle climbing community before relocating to Brooklyn, New York, in 2023 to be closer to family members.
James Lee, a friend and fellow climber, indicated that Chiu was a respected figure who frequently volunteered as an instructor with the Boeing Employees Alpine Society. Lee noted that Chiu regularly introduced newcomers to mountaineering, ice climbing, and rock climbing techniques, and could typically be found pursuing these activities on weekends.
In social media posts prior to his Alaska expedition, Chiu reflected on his climbing experiences and his decision to return to alpine mountaineering after a hiatus during the COVID-19 pandemic. He expressed concerns about his skills potentially declining while living in Brooklyn and working a desk job.
On May 19, Chiu wrote about his upcoming trip to Alaska, stating his intention to climb what he referred to as the world’s third-highest peak. Chiu expressed that “I don’t want to know what happens to a dream deferred” when explaining his motivation for the expedition.
The West Buttress route where the accident occurred is considered the most popular and accessible climbing path on Mount McKinley. Despite its reputation as the easiest route, it has witnessed multiple fatal accidents since 1980, with 15 climbers losing their lives along this path according to park statistics.
Park officials noted a similar incident occurred at the same general location in 2010, when an unroped French mountaineer fell to his death toward the Peters Glacier. That climber’s body was never recovered from the terrain.
The National Park Service reports that falls represent the leading cause of death at Denali National Park. Since 1932, 125 climbers have died within the park’s boundaries, including three fatalities during the 2024 climbing season.
Current climbing conditions show approximately 500 mountaineers on Mount McKinley during what officials describe as the busiest period of the climbing season. The season typically runs from early May through early July, with mid-May to mid-June representing peak activity levels.
Park registration records indicate 936 climbers signed up for the 2025 climbing season. As of late May, 230 climbers were already positioned on the mountain, with 17 having completed successful summit attempts before Chiu’s accident occurred.
Mount McKinley, also known as Denali, stands at more than 20,000 feet elevation, making it the tallest mountain in North America. The peak is located within Denali National Park, which encompasses more than six million acres of Alaska wilderness. Ski mountaineering, the activity Chiu was pursuing, involves ascending mountain routes with specialized equipment before skiing back down the slope.