The four-storey building in Luliang city housed both offices and dormitories, and was used mostly by miners for showering and holding meetings, the provincial government said.
There were more than 200 lockers in the building and 1,700 baskets holding miners’ work gear, a spokesman told reporters on Friday.
The blaze started during a shift change in the morning, miners told local media.
Some workers back from the night shift were still showering, while others were coming up the mining shaft. About 10 workers smashed a window on the fourth floor and climbed down a water pipe to escape.
At least 38 people were injured.
President Xi Jinping, who was in the United States at the time, sent instructions for local authorities to enforce more safety measures and eliminate “hidden risks” in key industries, state media reported.
“It is an extremely profound lesson,” he said, according to Xinhua.
Local police had detained 13 suspects, the government spokesman said on Friday. All mining firms in Lishi district, the part of the city where the accident occurred, have also been told to suspend production.
The State Council, China’s cabinet, had sent a team to oversee the rescue work, state broadcaster CCTV reported.
The National Health Commission has also sent a team to guide medical treatment of those injured.
Meanwhile, China’s emergency management minister, Wang Xiangxi, warned of increased fire hazards in the winter as he called for thorough checks in mining industry buildings including offices, dorms and cafeterias. Large shopping malls, restaurants, hospitals, schools and elderly homes should also undergo checks, he said on Friday.
China’s coal producers are under constant scrutiny over accidents, often caused by lax safety standards and poor enforcement.
Public records show that Yongju Coal Industry, owner of the mine connected to the stricken office building, had been punished and fined 11 times from 2017 to 2022 over pollution and safety risks.
Earlier this year, a government investigation team in Shanxi published a report on the local Jingcheng Coal Mining Company, where three workers were killed in a shaft collapse in September last year.
The company had hidden 40 production accidents from the authorities since 2007, including the deaths of as many as 43 miners, the report released in July said.
It said the company would reach out to miners’ families before news of the accident got out and offer to buy their silence with huge rewards.