The explosion occurred just before 6 a.m. local time, when 230 people were at the mine. Of those, 157 were evacuated in the initial hours after the blast, including 14 injured and one dead.

The Zasyadko mine is one of the most dangerous coal mines in Ukraine. It’s estimated that 240 people have perished at the mine since 1999—101 miners were killed in another incident in 2007.

An emergency services official told Sputnik News that, “this did not happen because of shelling.” Separatist leader Aleksandr Zakharchenko issued an order to close the mine a month ago, but managers ignored the order because the mine legally belongs to Ukraine.