Four Chinese quarrymen killed by carbon monoxide poisoning inside cave

Four Chinese quarrymen died from carbon monoxide poisoning while extracting stalactites in an underground limestone cave, mainland media reports.

Firefighters from Wenshan city, in southwestern Yunnan province, were alerted on Monday afternoon after a report that the men had become trapped inside a remote karst cave, the China News Service reported.

It took the firemen 90 minutes to reach the entrance to the winding cave, which stretches for about 200 metres underground, and had become filled with carbon monoxide gas.

They initially pulled out two of the quarrymen, who had become trapped near the entrance of the cave, before using a safety rope to descend further.

They found another quarryman lying in a coma more than 150 metre deep inside the cave, and spent 40 minutes before getting him outside the cave.