The Yuanyang colliery outburst occurred at the privately run Yuanyang colliery

Coal mining

The goal of coal mining is to obtain coal from the ground. Coal is valued for its energy content, and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United States,...

 in Puding County

Puding County

Puding County is a county of Guizhou, China. It is under the administration of Anshun city....

, Anshun

Anshun

Anshun is a prefecture-level city in China in the southwestern province of Guizhou where the famous Huangguoshu Waterfall is located. Within the borders of its prefecture one also finds attractions such as Long Gong Dragon Caves and the Getu River. As of 1999, it had a population of 217,215...

, Guizhou

Guizhou

' is a province of the People's Republic of China located in the southwestern part of the country. Its provincial capital city is Guiyang.- History :...

, People's Republic of China

People's Republic of China

China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

, at 9:40 p.m. on 13 May 2010. At least 21 people were killed and at least five were wounded.

Thirty-one miners were inside the shaft at the time of the outburst

Outburst (mining)

An outburst is the sudden and violent ejection of coal, gas and rock from a coal face and surrounding strata in an underground coal mine. When outbursts occur, they can be very serious events, possibly even resulting in multiple fatalities....

, and ten of them walked out alive. Rescuers searched in vain for others. There were genuine fears that an unknown quantity of unregistered miners may have been underground at the time. Half of the fleeing ten were still hospitalised and receiving treatment for carbon monoxide poisoning

Carbon monoxide poisoning

Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide . Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect...

 the following day. 24 miners were initially reported as being trapped, with seven escaping the mine.

An early investigation revealed explosives were responsible for the burst. The explosives were used for illegal mining which had been underway in the colliery. According to deputy director of the State Administration of Coal Mine Safety Wang Shuhe, "local authorities did not fully perform their duties, and occasionally even abetted or sheltered illegal activities". He visited the scene as part of the investigation. Work at all of Puding's collieries was suspended. Guizhou surveyed its coal mines for safety reasons on 15 May 2010. Guizhou's vice-governor Sun Guoqiang

Sun Guoqiang

Sun Guoqiang is a Chinese baseball player who was a member of Team China at the 2008 Summer Olympics.-References:* 2008 Olympics Team China*...

 said authorities should have checked the mine and asked officials after the burst: "Did anyone of you visit the mine after approving the shaft maintenance project"?

The incident had severe consequences for county-level and township officials: five were suspended or fired altogether when the full extent of what had occurred was realised. Vice head of Puding, Wu Guohong: county director of work safety supervision administration, Xu Dongfeng: county director of coal mining administration, Hu Yingze, were among these. The mine's owner, Li Renjie, vanished without a trace as authorities attempted to find him.