The OPP closed the main road near Bath on Tuesday night following heavy traffic collisions.
Provincial police released the information after 9 p.m. saying highway 33 was closed due to an accident on Jim Snow Drive.
The OPP said six people were injured in the crash, and four people had to be evacuated. Police have yet to release any information on the severity of the injuries.
A detour was made and the main road was only opened after 5am on Wednesday.
Photos posted in the Global News from the accident show at least one car badly damaged on the right side. At least one other car can be seen in the photos.
The OPP requests anyone with information about the investigation to contact them at 1-888-310-1122.