Twenty-one people tragically lost their lives after being met with hail, freezing rain, and high winds as they ran a 62-mile ultramarathon in China.
As reported by the Guardian, the fatal race took place in the Yellow River stone forest in China's north-western Gansu province. It saw an additional eight runners sustain non-life-threatening injuries, according to the outlet.
Over 700 rescuers and army personnel resorted to using thermal-imaging drones and radar detectors in an attempt to locate the runners who had been caught up in the storm.
Baiyin city mayor, Zhang Xuchen, said on Sunday, per the Guardian:
"At around noon, the high-altitude section of the race between 20-31km was suddenly affected by disastrous weather.
"In a short period of time, hailstones and ice rain suddenly fell in the local area, and there were strong winds. The temperature sharply dropped."
Zhang went on to explain that after the rescuers were sent out, the weather conditions had begun to worsen at around 2:00PM local time. As a result, the ultramarathon was immediately called off and local authorities dispatched more rescuers to help find the runners.
"This incident is a public safety incident caused by sudden changes in weather in a local area," he said, adding that provincial authorities will soon investigate the cause of the deaths.
Overnight on Saturday, temperatures in the mountainous region continued to decline and rendered the search operation "more difficult".
Some have criticized the authorities for their inadequate planning with regards to the dangerous conditions - despite the fact that a "significant" decline in temperatures had been forecast in most parts of Gansu over the weekend.
"Why didn’t the government read the weather forecast and do a risk assessment?" one commenter wrote on Chinese social media, according to the paper.
Another critic added: "This is totally a man-made calamity. Even if the weather is unexpected, where were the contingency plans?"
At a news briefing on Sunday, Baiyin officials apologized for the avoidable outcome of the sports event and added that they were responsible for the tragedies that occurred.
An investigation into the cause of the deaths is underway.