EAST PALESTINE, Ohio - East Palestine emergency crews have officially began the controlled release of toxic chemicals in the air.

This controlled release is in response to a train derailment that occurred late Friday evening which resulted in vinyl chloride getting released into the air.  Currently, there is a large cloud of dark smoke rising from the scene.

All East Palestine residents have been ordered to evacuate the area, as Ohio Governor Mike DeWine warned that exposure to these chemicals could lead to severe lung and skin injuries or even death.

Emergency officials say this could last between one to three hours and Governor DeWine says he's unsure when residents will be allowed to return home.

RELATED COVERAGE: