It would take at least another 15 days to reach a large amount of debris to reach the miners who have been trapped since an explosion 11 days ago at a gold mine in the east of the country. ChinaAuthorities said.

The Yantai City government said the mine shaft was blocked 350 meters (1,000 feet) below the surface by 70 tons of debris extending another 100 meters. „Based on expert assessments, the extent of blockage … is far from expectations.”

Earlier on Thursday, state media said a miner had died of wounds to the head in the blast. Of the remaining 21, Rescuers called 10One of them is said to be alive in an adjacent room and the status of the ten others is unknown. Two of the survivors are said to be in poor health.

Rescuers have delivered food, medicine and other supplies to 11 people and are working to clear debris and improve ventilation. They were trying to remove cages and other debris blocking the main shaft while digging other shafts for communications and ventilation and possibly to raise workers to the surface. Official media reports said the drilling reached depths of about 700 meters (about 2,000 feet).

Mine managers were arrested for waiting more than 24 hours before reporting the accident, the cause of which has not been made public. The mine was in Qezia, Shandong Province, under construction when the explosion occurred on January 10.

Increased supervision has improved safety in China’s mining industry, which has averaged 5,000 deaths a year, but demand for coal and precious metals continues to push the corner cut, and two accidents in Chongqing last year killed 39 workers.