The tank car, carrying approximately 30,000 gallons of styrene, was just four miles short of its destination when the leak occurred.

Authorities in Hamilton County, Ohio, said the rail car was leaking styrene, a toxic and flammable chemical that is used to make plastic and rubber.

Hundreds of people returned to their homes Wednesday night after firefighters responded to a railyard for a reported chemical leak in Ohio.

A Train car in Hamilton County, Ohio had an open valve that leaked styrene and forced an emergency evacuation for anyone within a half mile radius of the area. (Credit: Aaron Vetter/Facebook)

An evacuation order remains in effect for residents in an Ohio community as crews work at the scene of a dangerous chemical leak

Aerial video shows fire crews putting water on a train car that appears to be leaking chemical Boise State moves into the 12-team field after Northern Illinois lost in Week 4. This college football season is still devoid of major upsets, but some teams have played tougher schedules than others.

Residents near Cincinnati were urged to leave their homes due to the chemical leak as officials said there were concerns about a possible explosion.

The leak in Whitewater Township involves styrene, a gas used in producing plastic, rubber, fiberglass and other structural material.