Updated

More than a thousand residents in Kentucky have been told to leave their homes because of a chemical fire from a derailed train car near Louisville that left three workers badly burned.

Officials in West Point, a short distance from the fire, ordered its nearly 1,000 residents to leave due to the potential health hazards posed by the burning chemicals. The order also affected nearly 140 residences in southwest Louisville. Residents just outside the evacuation zone have been told to stay indoors.

Authorities say the blaze broke out while workers were using a cutting torch or welder to separate two of several cars that derailed Monday evening.

Authorities say one of the workers is in very critical condition, another in critical condition and the third in serious condition.

The burning rail car was only a few feet from other derailed tankers carrying another dangerous chemical.