After more than a week of fear, families of the trapped miners being brought to the surface were relieved that their loved ones had avoided becoming another grisly statistic in the world's deadliest coal mining industry.

The Wangjialing colliery flooding would have been China's worst mining disaster since August 2007, when 181 workers died at two flooded coal mines – 172 at one mine – in Xintai, eastern Shandong Province.

Accidents killed 2,631 coal miners in China last year, down from 6,995 deaths in 2002, when the government set out to clean up the industry's appalling safety record.

Coal accounts for 69 per cent of the primary energy in China – 42 per cent higher than the world's average – and the country's miners often end up as victims of the rush to provide the coal needed to fuel China's factories.

The government has made significant progress in making it safer by shutting illegal mines and improving safety standards, and has introduced new measures, such as requiring that experts be on hand to make sure that shafts are evacuated when gas reaches certain levels.

Many of the workers die in illegal unregulated mines that are dotted around the country, run by unscrupulous mine bosses who think only in terms of meeting targets. While state mining authorities have been battling to wipe out corruption, enforcement is difficult and the demand for coal is enormous. Despite the best efforts of the authorities, still the small, illegal mines prevail. Officials close local illegal mines, but it is common for them to spring up again just weeks after they are shuttered.

Old abandoned tunnels are posing a new risk as the country digs deeper for the coal it needs to fuel its economic boom.

Last month 32 workers were killed in an incident similar to the one in Wangjialing when underground water flooded a mine under construction in north China's Inner Mongolia Autonomous Region.

China, the world's top emitter of greenhouse gases, has pledged to reduce its reliance on coal. It has set a target of generating 15 per cent of all electricity from renewable sources by 2020. However, efforts to improve the country's environmental record are hampered by booming demand.