LAMAR, Neb. - Authorities in southwest Nebraska are investigating a structure fire involving chemicals 23 miles west of Imperial on Wednesday afternoon. 

The Chase County Sheriff's office says the fire happened at the intersection of Highway 6 and 314 Ave., the site formerly known as Lamar Fertilizer. They told people to stay away from the area, and advised people stay out of the smoke plume and shelter in place. 

Some area residents elected to evacuate the area all together.

Highway 6 was closed from west of Imperial to Holyoke, Colo while fire fighters from Lamar, Imperial, Grant, Venango, and Ogallala extinguished the blaze. 

Traffic was rerouted onto county roads muddied by falling snow. Witnesses say semi-tractor-trailers and on-lookers were sliding off roads into ditches because of the muddy conditions.

This is a developing story. Stay with News Channel Nebraska for the latest.