UPDATE: One person is dead after a three three-car crash on Boundary Road, just south of the 417, sent three people to hospital Wednesday night.
A 50-year-old man suffered "severe multi-system trauma" and was taken to hospital in critical condition. A 40-year-old man suffered a head injury.
A 42-year-old woman suffered minor injuries and was released.
Police say it appears there were witnesses who stopped to assist at the scene but did not speak to police. Investigators are asking those witnesses to come forward.