(ZHU XIANG)

Rescuers walk out of a coal mine pit in Yuzhou, central China's Henan Province, where a gas explosion killed 37 people on October 16.

Two hundred and thirty-nine workers of the Pingyu Coal & Electric Co. Ltd., who were working underground when 173,500 cubic meters of gas leaked, survived the accident.

It was the second explosion in the mine in two years after 23 miners were killed on August 1, 2008.

Luo Lin, Director of the State Administration of Work Safety, who is leading a probe into cause and responsibilities for the burst, said the coal mine had major flaws in safety management and had failed to install measures to prevent gas leaks.