The hashing power of top Bitcoin mining pools located in Northwest China appears to have plummeted due to a regional blackout to enable safety inspections.

The news was reported by Wu Blockchain, the author of Chinese crypto newsletter Wublock, who noted significant drops in the hash rate of several major pools — with Antpool crashing 24.5%, Binance Pool dipping 20%, BTC.com falling 18.9% and Poolin dropping by 33%.

According to an article on Chinese media outlet Wu Talk, the region of Xinjiang is currently experiencing a “comprehensive power outage safety inspection.”

The inspections follow a recent flooding accident at a coal mine in Xinjiang that saw 21 miners temporarily trapped at three different locations. The mine was swamped in a sudden flood while making technical upgrades, resulting in communication interruptions and power outages underground. Nearly 1,500 rescue personnel were deployed to the mine to assist with the emergency.

Xinjiang is a major source of global Bitcoin hash rate, with the Cambridge Bitcoin Energy Consumption Index, or BECI, estimating the region currently represents nearly roughly 36% of China’s combined hashing power. With China comprising two-thirds of global mining power, BECI estimates Xianjian to comprise 23.3% of the global hash rate.

According to Ycharts, the outages appear to have driven a roughly 2.2% drop in the Bitcoin network’s combined hash rate in the past 24 hours, which has slid from 169.4 million terahashes per second, or TH/s, to 165.8 TH/s as of this writing.