Two children have been sent to hospital after a collision involving three vehicles on the 401 eastbound at Winston Churchill.
One of the children is just 4-years-old and police say, is in critical condition in hospital.
A 2-year-old child and an adult have also been taken to hospital, but their injuries aren't considered serious.
Police say for some reason, the SUV lost control and got tied up with a transport truck.
The driver of the truck has remained at the scene and she is co-operating with police.
The 4-year-old was ejected from the vehicle.
So far, police haven't laid any charges.
OPP