Three people are dead after a collision on Highway 407 west of Toronto.

The incident occurred around 3 p.m. Sunday after two vehicles and bus collided near Missisuaga Road.

It's believed a tire malfunction caused the driver of a Chevy to lose control and swerve into the path of a bus.

The car was T-boned, caught fire, and rolled into a ditch.

When officers and emergency crews arrived they located three victims.

Two were pronounced dead at the scene. A third person was in critical condition but pronounced dead an hour later.

Paramedics say all three of the vicitims were inside the Chevy.

Their identities have not yet been released.

With reporting from Tracy Tong