A runner participating in the Cocodona 250 ultramarathon in Arizona died after experiencing a medical emergency during the race, organizers announced Tuesday.

The participant suffered what organizers described as a "serious medical emergency" during the 253-mile endurance race across northern Arizona trails. The race began Monday and is scheduled to continue through Saturday.

The Cocodona 250 is considered one of the most challenging ultramarathons in the United States, featuring more than 38,000 feet of elevation gain across difficult terrain in northern Arizona. The multi-day event tests runners' endurance across extreme distances and challenging conditions.

Race organizers said in a statement posted on Instagram that the event will continue in honor of the deceased runner. The statement did not provide details about the nature of the medical emergency or the runner's identity.

Ultramarathons, which are races longer than the traditional 26.2-mile marathon distance, have grown in popularity in recent years despite their extreme physical demands and inherent risks.