Fourteen people were killed and seven others injured early Monday when a shift bus fell off a 25-meter cliff in Russia’s Sakha Republic, local authorities reported.

The crash occurred on a road operated by the Denisovsky Mining and Processing Plant. The bus, carrying over 30 workers, veered off the road and overturned, according to Xinhua.

The driver was among the dead, while two of the injured remain in serious condition. Emergency crews deployed 44 personnel and 13 vehicles to the site.

An investigation into the cause is underway, Xinhua reported.