A Chatham man sustained life threatening injuries after a head-on collision between a van and an ambulance.
Police say the vehicles were travelling in opposite directions on Highway 40 around 10:30 a.m.
Investigators are still piecing together the events leading up to the crash.
The driver of the minivan, 60-year-old Geoffrey Brereton, was airlifted to a London hospital.
Earlier reports claimed Brereton had died in the crash. However that information was incorrect, and he remains in hospital in critical condition.
The driver of the ambulance was taken to hospital with minor injuries.
Police say the ambulance was not on call and there were no patients inside.
With files from CTV Windsor
