Coal mining is by far China's most dangerous occupation, with cave-ins, floods and explosions prevalent. Newspapers almost every day carry dispatches on the latest mine tragedy.

A Chinese coal miner is 128 times more likely to die than his U.S. counterpart. Official statistics show Ukraine is even more dangerous than China.

"If there's a death, they (coal mine owners) try by every means possible to cover it up, so people don't know about it," said a coal entrepreneur.

Local officials feel obligated to report mining deaths to the central government in Beijing only when accidents take several victims, he said.

China's large state-run mines, which produce about half the country's coal, usually contain gas monitoring and safety equipment. Risks are far greater in China's 23,600 small mines, operated by townships or illegally contracted out to individuals. Many private mines overseen by villages and townships are the only source of tax revenue for the communities.

Villages refuse to shut mines down for safety reasons. "There's such enormous money that can be made," said a local coal broker.