Assertion: coal mine | /r/HasProperty | one of the most hazardous
Facets:
value: due to enormous working depths
type: CAUSE
Source sentences:
text: The coal mines of Donbas are one of the most hazardous in the world due to enormous working depths (down from 300 to 1200 m) as a result of natural depletion, as well as due to high levels of methane explosion, coal dust explosion and rock burst dangers.