Russian authorities opened a criminal investigation into a suspected methane-gas explosion at a Siberian coal mine that killed more than 50 people and left dozens hospitalized, casting a spotlight on a key industry for the country that in recent years has been plagued with accidents.
The exact circumstances of Thursday’s explosion at the Listvyazhnaya mine, in the Kemerovo region of southwestern Siberia, are still being investigated. But preliminary assessments found that toxic fumes began to fill the ventilation point in the mine some 820 feet underground and the workers were suffocated, investigators said.
“The probable cause of the accident is an explosion of a methane-air mixture,” Sergei Tsivilyov, Kemerovo’s governor, said in a Telegram message Friday. “The exact reasons will be established by the commission.”
Six rescuers were among the dead and Mr. Tsivilyov said one person had been found alive and taken to a hospital where almost 50 people were being treated, including miners and rescuers.
“The suspects inappropriately fulfilled their duties to supervise the implementation of industrial safety requirements at a hazardous production facility,” the Kemerovo branch of Russia’s main investigations agency said in a statement. The officials earlier this month signed off as having checked the mine shaft, but it was established that they hadn’t, investigators said.
On Thursday, three mine managers who investigators said also violated certain industrial safety requirements were detained.
The explosion wasn’t the first deadly accident at the Listvyazhnaya mine, where in 2004, a methane explosion left 13 miners dead.
Russia has suffered at least 11 major mining accidents since 2000, in which 10 or more people have died, according to state news agency TASS, which cited official data.