Six North Korean mine workers died and one was rescued 10 days after the collapse of a newly-opened tunnel at the Unryul Mine in South Hwanghae Province on January 9, ruling party organ the Rodong Sinmun reported on Monday.

A few minutes after 46-year-old chief engineer Ann Yun-seok and six other miners entered the tunnel, an “expected huge collapse” occurred.

“This is a great catastrophe seen for the first time since the mine was developed,” Rodong reported. “The damage was beyond imagination.”

“The amount of mud which was moved from the [collapsed] tunnel during the rescue operation reached [the weight