It appears a medical condition caused a crash in front of Devonshire Mall on Monday afternoon.
Windsor police were called to the scene just before 5pm for the crash on Howard Ave.
The roadway was closed for several hours while police investigated.
Police report a northbound orange Dodge Calibre veered into the southbound lane on Howard Ave. and hit a gray Honda Civic. People nearby came to the aid of the man behind the wheel of the Calibre, as he was suffering from a medical condition, to give him CPR until paramedics got in scene.
The 48-year-old man had his vital signs absent before being revived and sent to hospital in critical condition.
The 61-year-old woman driving the Civic suffered minor injuries and was also sent to hospital.
The man remains in hospital in critical condition.