A tractor-trailer collided with a minivan in Mapleton Township on Tuesday morning, sending both drivers to hospital, according to Wellington County OPP.
Police say the collision occurred near the intersection of Wellington Road 86 and Wellington Road 10.
Their preliminary investigation revealed the minivan was headed south Wellington Road 10 while the tractor-trailer was going west on Wellington Road 86 when the collision occurred.
Police say there is a stop sign for Wellington Road 10 on both sides of the intersection.
They say the cause of the crash remains under investigation.
The driver of the minivan, a 66-year-old woman from Moorefield, was taken to an area hospital before being transferred to a London hospital with life-threatening injuries.
The truck driver, a 65-year-old Woodstock man, was taken to a local hospital with non-life-threatening injuries.
Police say the Ministry of Labour and the Ministry of the Environment have both been notified about the crash.
Police are asking any witnesses to call at 1-888-310-1122.