HEFLIN, Ala. — Police say a deadly crash involving a large truck led to an explosion on an interstate in eastern Alabama, and authorities were telling motorists to avoid that stretch of roadway since lanes were blocked.

Heflin Police Chief A.J. Benefield said in a statement on social media that the wreck happened around 2 a.m. Wednesday on Interstate 20 in Heflin.

Benefield said a car heading east on I-20 crossed the median and struck the westbound truck.

Benefield said the explosion happened due to the load the truck was hauling. He said hazardous materials crews were at the scene early Wednesday.

Police described the crash as a “fatality wreck,” but did not immediately provide any additional information about the motorists.

Heflin is about 75 miles (120 kilometers) east of Birmingham.