2013 Horlivka chemical accident
An industrial chemical accident occurred on 6 August 2013 at the private limited company Concern Stirol JSC, part of Ostchem Holding AG, in the city of Horlivka, Ukraine. Ammonia was released in the air and five people were killed and 23 people were injured from exposure to the gas.
Source: Wikipedia — 2013 Horlivka chemical accident (CC BY-SA 4.0)