For details, see this New York Times story:

http://www.nytimes.com/reuters/2009/11/20/world/international-us-china-mine-explosion.html?_r=1

More information here:

http://www.nytimes.com/2009/11/22/world/asia/22china.html?ref=world

The second story says that at least 87 died in the accident.