Native language of the population of the city of Donetsk as of the Ukrainian Census of 2001 : Donetsk and the surrounding territories are heavily urbanised and agglomerated into conurbation . The workforce is heavily involved with heavy industry , especially coal mining . The city is an important center of heavy industry and coal mines in the Donets Basin ( '' Donbass '' ) . Directly under the city lie coal mines , which have recently seen an increase in mining accidents , the most recent accident being at the Zasyadko mine , which killed over 100 workers
Zasyadko mine
2007 Zasyadko mine disaster
Donetsk