The explosion occurred late on Friday at the Liushenyu coal mine in Qinyuan County, where 247 workers were on duty underground at the time of the accident, according to state news agency Xinhua. Rescue operations were continuing on Saturday as authorities worked to locate remaining workers and assess conditions at the site.

The mine is operated by Shanxi Tongzhou Group Liushenyu Coal Industry, a company established in 2010 and controlled by Shanxi Tongzhou Coal Coking Group, according to corporate records.Local emergency management authorities said the cause of the explosion remained under investigation.

Shanxi, China’s leading coal-producing region, has long been at the center of the country’s mining industry and has experienced numerous major industrial accidents over the decades.President Xi Jinping ordered authorities to spare no effort in treating the injured and conducting search-and-rescue operations, according to Xinhua.

He also called for a comprehensive investigation into the disaster and accountability for those found responsible under the law.Premier Li Qiang urged officials to ensure the timely release of information and enforce rigorous accountability measures as investigations proceed.

Xinhua reported that executives linked to the company operating the mine had been detained following the accident.Provincial authorities dispatched seven rescue and medical teams comprising 755 personnel to the disaster site, according to Qinyuan’s emergency management bureau.

China has significantly reduced fatalities in its coal mining sector over the past two decades through stricter safety regulations, modernization efforts and tougher enforcement standards.

Nevertheless, gas explosions and other underground hazards continue to pose risks in some mining operations.

The previous deadliest coal mining disaster in China occurred in 2009, when a coal and gas outburst at a mine in Heilongjiang province killed 108 people and injured 133.

The incident occurred at an aerospace facility in Garden Grove, southeast of Los Angeles, where a storage tank holding about 7,000 gallons (26,000 liters) of methyl methacrylate developed a leak. Emergency officials warned that the situation posed significant risks to nearby communities due to the chemical’s flammable nature and the possibility of a thermal runaway reaction.

Incident Commander Craig Covey said emergency planners were preparing for two primary scenarios: a complete tank failure resulting in a large chemical spill or an explosion that could affect neighboring tanks containing fuel and other hazardous materials.

“We are setting up these evacuations in preparation for these two options,” Covey said, describing the threat as serious and requiring immediate precautionary measures.

Garden Grove Police Chief Amir El-Farra said approximately 40,000 people were covered by the evacuation order, although several thousand residents chose to remain in their homes despite warnings from authorities.

Emergency crews continuously sprayed water on the tank in an effort to reduce its temperature and stabilize conditions. Later on Friday, Covey reported that cooling operations had succeeded in lowering the tank’s temperature to about 61 degrees, closer to what officials described as a safe operating range.

Authorities continued searching for alternatives that could further reduce the risk of either a major spill or an explosion.

Orange County Health Officer Regina Chinsio Kwong said the evacuation zone was established to protect residents from potential exposure to hazardous vapors in the event of a catastrophic failure.

She urged the public to report any detection of a strong fruity odor associated with methyl methacrylate, while noting that the smell alone did not necessarily indicate harmful exposure levels.

No injuries had been reported as of Friday evening, and officials had not determined the cause of the leak, which was first identified on Thursday.

Emergency responders were also preparing containment measures to prevent any released chemical from entering storm drains, waterways or channels that flow into the Pacific Ocean.

According to the U.S. Environmental Protection Agency, methyl methacrylate can irritate the skin, eyes and respiratory system. Acute or prolonged exposure may also result in respiratory and neurological effects.