... at the time of the explosion.
THE GUARDIAN
http://www.theguardian.com/world/2015/mar/04/explosion-coal-mine-donetsk-killed
At industryabout.com: Zasyadko Coal Mine ...
27 January 2015. Hundreds of miners are trapped in a mine in eastern Ukraine after a shell hit the power station that provides its electricity. Almost 500 workers were inside the Zasyadko coal mine, in ...