Peel police said one person is dead after a dump truck and another vehicle collided on Airport Road near the International Centre in Mississauga.
Police said there were three occupants in the car. The other two have been rushed to a trauma centre.
Peel paramedics said one of the injured is a 9-year-old girl, who is in serious condition. Paramedics also transported a 70 year old woman who is now in stable condition.
Police said all the victims are from the London area.
Police said the collision happened shortly before 10 am and the driver of the dump truck stayed on scene.
Airport Road was closed between Derry Road and Northwest Drive in both directions for much of the day but has now re-opened.
The Major Collision Bureau is investigating, said Peel police spokewoman Const. Rachel Gibbs.
“The placement of the sun, the functioning of the traffic lights, the mechanical function of the vehicles, what the drivers were doing. All of that will be part of the investigation,” she said.
With files from Catherine McDonald.