Still, disasters are still common. And coal mines, with noxious and explosive gases, remain deadly. At least 16 people died of carbon monoxide poisoning in a coal mine in southwestern China in September, and 23 more were killed at a coal mine in the same city, Chongqing, in December.
Gold mining, by contrast, is generally safer but not without risks.
The Jan. 10 blast at the Hushan gold mine near Yantai trapped 22 miners. On Jan. 17, rescue workers were able to make contact through a narrow, drilled channel. A note sent up by the miners said that 11 were trapped in one section, one in another and 10 were unaccounted for. Four were injured, and all were suffering from exhaustion in the wet and smoky tunnels.
“Hope that the rescue will not stop,” they wrote. “We have hope, thank you!”
On Wednesday, one of the miners died of head injuries sustained in the explosion, the state news media reported.
In addition to several holes bored to deliver supplies and search for missing miners, rescuers began drilling a shaft to rescue survivors. Work on the main rescue shaft was expected to take at least 15 days because of tons of rubble blocking the route, officials said on Thursday.
But on Sunday, officials said that work on the rescue shaft had progressed much faster than expected.