A semi tanker rolled over and was leaking fuel about 9 p.m. Tuesday night near New Athens.
Multiple emergency crews responded to the scene at Heller Road and New Athens Darmstadt Road, according to the St. Clair County Emergency Management Agency's Facebook page.
Motorists were asked to avoid that area as crews closed roads and worked to stabilize and right the truck.
New Athens Fire Department was assisted by St. Libory Fire, Marissa Fire, Lenzburg Fire, the St. Clair County Sheriff's Office and Ameren Illinois.
Additional details were not immediately available Tuesday night.