Social-media users ask why some workers weren’t wearing mandatory tracking devices and why there were twice as many of them underground as disclosed by the private mining company

Official news agency Xinhua said the accident at Changzhi city's Liushenyu coal mine happened on Friday evening and 247 workers were trapped underground.

The explosion took place late Friday at the Liushenyu coal mine in Qinyuan county, where 247 workers were reportedly underground at the time of the incident. | World News