A methane blast at the Listvyazhnaya coal mine in Siberia's Kemerovo region killed 51 people on November 25. It was the deadliest mining accident Russia had seen since 2010. The explosion sent toxic smoke through the mine's ventilation system, suffocating miners and rescue workers who came to their aid. But as miners at the Listvyazhnaya told Meduza, the mine's methane levels had been critical for about two weeks beforehand, ever since a rock collapse "completely crushed" a ventilation shaft. The Listvyazhnaya's management, however, opted against shutting down operations. According to the miners Meduza spoke to, their bosses were afraid they wouldn't fulfill the production plan.