At least 21 ultramarathon athletes died after brutal weather swept across a mountainous area of northwest China during the Huanghe Shilin Mountain Marathon, state media reported Sunday.
An additional 151 participants in the 62-mile race in Baiyin City in Gansu Province were accounted for, and eight people were hospitalized in stable condition, local rescue headquarters reported.
The officials cited a sudden, dramatic change in the weather during Saturday's race in the Yellow River Stone Forest. At about 1 p.m., hail, freezing rain and gales hit the area of the race's high-altitude stage as runners were climbing 6,500 feet above sea level in shorts and T-shirts.
"Participants suffered from physical discomfort and loss of temperature due to the sudden drop in air temperature," state media reported.
The temperature dropped again during the night because of the area's complex terrain and topography, making the search and rescue effort more difficult, authorities said. Among the dead was Liang Jing, 31, an ultramarathon champion and three-time winner of the race.
Participants posted videos requesting help in a WeChat group chat. Some of the runners went missing and the race was halted. Local governments initiated an emergency response and organized over 1,200 rescue workers to search for the missing athletes amid mudslides and localized flooding. Thermal-imaging drones, radar detectors and demolition equipment were brought in to aid the search.
Competitor Mao Shuzhi told Reuters it was hot one day before the race.
"Although the weather forecast said there would be wind and moderate rain in Baiyin on Saturday, everybody believed it would be mild,” she said.
She was about 14 miles along when the weather grew angry, and she decided to turn around.
“At first I was a bit regretful, thinking it might have just been a passing shower, but when I saw the strong winds and rains later through my hotel room window, I felt so lucky that I made the decision,” she said.
The province has set up an investigation team to look further into the cause of the incident, Baiyin City Mayor Zhang Xuchen said.
"As the organizer of the event, we feel a deep sense of guilt and remorse," he said. "We express our deep condolences and sympathies to the bereaved families and the victims."
Many WeChat group chats involving the event's organizer and participants had released weather warnings for Saturday on Friday night, officials said. The terrain along the running course is complex and there was a possibility of short-term extreme weather in the area, according to local weather authorities.
"In ultrarunning's biggest tragedy, 21 runners died during severe weather at China's Yellow River Stone Forest 100k on Saturday," the ultrarunning website irunfar.com said in a post Sunday. "We are at a loss for words in this horrific moment."
This article originally appeared on USA TODAY: China's Huanghe Shilin Mountain Marathon: 21 die in brutal weather