The Gansu ultramarathon disaster, which claimed the lives of 21 runners due to hypothermia, shocked the world in 2021. After that tragedy, ultramarathons globally adopted new safety protocols. But despite those changes, these races still carry serious risks. And now the endurance community is once again mourning as a runner passes away mid-race during the 2026 Cocodona 250-mile in Arizona.

On May 6, the official Cocodona shared the heartbreaking news on Instagram. “We are deeply saddened to share that a participant experienced a serious medical emergency today during the event and has passed away,” the organizers wrote.

According to reports, the runner was a woman in her 40s who collapsed near the Groom Creek Trailhead south of Prescott, Arizona, between miles 75 and 80 of the course. Even the Yavapai County Sheriff’s Office confirmed, “First responders attended to a woman in her 40s who was participating in the race and collapsed at a trailhead in the Groom Creek community south of Prescott, Yavapai County Sheriff’s Office spokesperson Paul Wick said on Wednesday.”

“Please keep the runner’s family, friends, fellow runners, volunteers, and first responders in your thoughts. We are deeply grateful to this beautiful community. The race is going to continue in their honor…,” the organizers said.

However, the runner’s name has not been disclosed, but the incident has clearly again shown the physical toll that ultramarathons can take on the body, particularly in remote areas. Even if you see the requirements of the Cocodona 250-mile, the truth is even more apparent.

The Cocodona 250-mile path travels through Arizona’s desert, forests, and mountain trails from Black Canyon City to Flagstaff. The 125-hour course is a challenge for the body and the mind, comprising over 38,000 feet of climbing across technical trails, dirt roads, and exposed sections. Yet Cocodona is not the first instance when ultrarunning has met tragedy.

Lessons from past tragedies still fall short in Ultramarathons

The 2021 Yellow River Stone Forest 100K remains one of the darkest moments in the sport.  The race took place in China, where 172 participants ran a mountain course at an altitude of 100 km. A sudden change in weather occurred around midday, bringing freezing rain, hail, and strong winds. This resulted in a sudden drop in temperature. Because of this, many runners were exposed to hypothermia.

Even though rescue teams were quickly called, the response was hampered due to poor communication in the remote area. In total, 21 runners lost their lives to harsh conditions. Following the tragedy, new measures were introduced for weather monitoring, mandatory safety equipment checks, and faster emergency response systems. However, the lessons were not fully completed, and even years later, similar incidents have continued.

Last year, a runner lost their life after having a medical emergency while running the Hardrock Hundred Mile Endurance Run in Colorado’s San Juan Mountains. Elaine Stypula, the 60-year-old athlete, collapsed near the first part of the race, near the Little Giant Trail. She was rapidly attended by rescue services, and despite administering CPR, she was declared dead.

The latest tragedy in the Cocodona 250 event brings the dark side of ultramarathons to the front again. The entire community is still hoping for better measures that could prevent such casualties in the future.