China’s lack of a free press, independent trade unions, citizen watchdog groups and other checks on official power makes cover-ups more possible, even though the Internet now makes it harder to suppress information completely.

Work-safety officials in Beijing complain that even more than in other industries, death tolls from accidents at coal mines are often ratcheted down or not reported at all. That is because of the risky profits to be made  by businessmen and corrupt local officials  exploiting dangerous coal seams with temporary, unskilled workers in thousands of illegal mines.

Just two weeks after the Lijiawa disaster, for example, officials in neighboring Shanxi Province announced that 11 people had been killed in a natural landslide. After another Internet-lodged complaint, investigators discovered that 41 villagers had been buried under a torrent of rocks and waste from an iron mine.

Even if underreported, the official death rate for China’s coal mines is astronomically high. On average, nine coal miners a day died in China last year  a rate 40 times that of the United States, according to the State Administration of Work Safety. Small mines, legal and illegal, accounted for three-fourths of the deaths but only a third of the production.

To be sure, the mines are much safer than just six years ago. Huang Yi, the deputy administrator of the work safety agency, said stricter scrutiny, regulations and the closing of 12,000 mines had cut the death rate by three-fourths since 2002. “There are some illegal coal mines that still operate because they are protected by local officials,” Mr. Huang said, but “fewer and fewer.”

Hu Xingdou, an economics professor at the Beijing Institute of Technology, argues that Beijing’s top-down approach can only do so much to make local officials more accountable.