(WANE) – A man is in critical condition Tuesday afternoon after a crash on Interstate 69 near Auburn that police suspect was caused by impaired driving.

Indiana Department of Transportation (INDOT) announced the lanes were closed between IN 8, near Auburn, and Exit 334/US 6, one mile south of Waterloo.

Indiana State Police (ISP) confirmed the crash happened around noon and involved a semitruck and a mowing tractor contracted by INDOT.

According to police at the scene, a semitruck veered off the interstate and hit a tractor on the right-hand side.

A man in the tractor suffered critical injuries, ISP said, and the driver of the semitruck was also taken to a hospital for further medical evaluation and chemical testing as required by law.

Authorities suspect the crash happened due to impaired driving.

According to ISP, the crash affected traffic in the area for nearly four hours and had traffic backed up for “several miles.”

The crash is still under investigation, and once it is finished, a full report will be sent to the DeKalb County Prosecutor’s Office for review of any warranted criminal charges.