LANZHOU - All ten workers have been confirmed dead after they fell off an overturned platform in a coal mine in northwest China's Gansu Province on Thursday evening, local authorities said Saturday.

The last deceased worker was lift from a deep shaft at around 1:15 am Saturday after rescuers pumped water from the bottom of the shaft, said a spokesman with the provincial bureau of work safety supervision.

The accident happened at 6:56 pm Thursday in the Huacaotan Coal Mine in Shandan County, Zhangye City.

The workers fell off the platform after it overturned more than 200 meters above the bottom of the shaft, which was inundated by deep water,  authorities said.

The coal mine, which was under construction when the accident happened, belongs to Zhangye Hongneng Coal Industry Ltd,.