Police and emergency services are at the scene of a serious car crash which has caused the closure of Brand Highway, near Muchea.
The crash occurred at 5am when two cars collided head-on.
It is understood that one person died and one has been flown to hospital.
Brand Highway in both directions from Bore road to Nolan Road are closed.
Police expect the highway to be closed for several hours and have advised motorists to take caution when approaching the area.
There were fog warnings for motorists in the metropolitan area this morning, but the warnings did not include areas to the far north of the city.