This happened around 11pm on TC Jester and Cypresswood Drive.
The impact of the crash caused the ambulance to roll over at least once with the patient, a doctor and a driver inside.
All three were taken to hospitals. The 81-year-old later died of her injuries, MPs said.
Two people inside the car were also taken to hospitals.
The conditions of the four people were not immediately known, but the driver of the car was critical at the time of the accident.
The ambulance, owned by the Acadian Ambulance Service, has a video camera on board and the images are being examined by investigators.
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