Two people were pronounced dead at the scene of a head-on collision on Saturday afternoon.
Police said it happened around 3:30 p.m. on County Road 12 near County Road 45 in the Township of Mapleton.
Crews on scene managed to rescue one trapped passenger who was airlifted to London hospital.
Officials on scene said the woman was trapped in the vehicle for 90 minutes and was taken to hospital in critical, life-threatening condition.
"I talked to one of the ladies in the accident, checked on a couple other people and I have a window breaker and we got in so I could check the pulses and that sort of thing," said Marjorie Taylor, a nurse who was driving by the collision.
County Road 12 between County Road 45 and Fourth Line is closed and police said it will remain closed for several hours while the investigation continues.
Anyone who may have witnessed the crash is asked to call police at 1-888-310-1122.
