(CBS) — All lanes on the southbound Tri-State have been closed after an accident involving two semis.

Illinois State Police says crews are working to open all but two lanes so traffic can start moving again.

READ MORE: Mobile City Hall Bringing City Services To Little Village Tuesday

The crash happened around 5 a.m. when two semis collided on the southbound Tri-State near the Hinsdale Oasis.

READ MORE: Police Release Video Of Suspects Wanted In Death Of 18-Year-Old Azul De La Garza

One the the trucks was carrying hydrochloric acid and other chemicals, which resulted in a hazardous materials response. The side of one of the semis was completely shredded.

The southbound Hinsdale Oasis parking lot has also been evacuated.

MORE NEWS: Chicago Police Officers Refusing To Report Vaccine Status Expected To Protest Outside Police Headquarters Tuesday

Backups in the southbound lanes stretched for at least four miles.