Four workers were confirmed dead and 90 remained underground after carbon monoxide exceeded limits Friday night at the Liushenyu coal mine in Qinyuan County, Changzhi.
At least 247 workers were in the mine when the accident struck at 9:43 p.m.; by 3:33 a.m. Saturday, rescuers had brought 157 to the surface.
Sixteen of those still underground were reported in critical condition, underscoring the urgency of the ongoing rescue operation.
The accident in Shanxi, a major coal-producing province in north China, adds to scrutiny of mine safety as emergency crews continue search and rescue efforts.
China has developed advanced rescue robots. So why are 90 miners still trapped underground?
As global coal demand peaks, are deadly mining accidents the unavoidable price for energy?