Raspadskaya Mine
The first blast occurred at 20:55 Moscow Summer Time (16:55 UTC) with the second at 01:00 MST (21:00 UTC). The explosions were confirmed by investigators to have been caused by methane gas.
A secondary explosion was reported approximately four hours later, with 20 rescue workers now among those missing. The second explosion caused a collapse of the mine's ventilation shaft, drastically reducing the flow of fresh air into the mine.
Rescue efforts were suspended after the second blast. By 18 May 2010, 66 people were confirmed to have died, at least 99 injured and 24 remained trapped underground. The Russian emergencies minister confirmed that rescue efforts were ongoing, saying "There is always a chance of recovery." Rescue work resumed late on May 9 after methane levels had dropped below safety limits and, at the peak of the operation, 560 people were involved with aid being sent from other parts of Russia
An emergencies ministry officer earlier said the explosion occurred at 8:55 p.m. Moscow time (16:55 GMT). There were 359 people in the mine at the moment of the first blast, and 282 people, including those killed, were already taken to surface.
This accident claimed the lives of 91 people.
The accident at the Raspadskaya coal mine is believed to have been caused by poor observation of safety regulations.
The Russian industrial safety watchdog detected over 1,400 safety violations at the mine in 2009 and in January-April 2010 and suspended production five times.