Road closures are in place on South Western Highway between Dobson Road and Robertson Drive in Glen Iris.
Major crash is investigating a fatal crash that occurred on South Western Highway near Waterloo overnight.
Around 9:15 a red 1978 Ford transit van was travelling south east along the South West Highway when it collided with the rear trailed of a white 2007 Volvo prime mover travelling in the same direction.
The Volvo was towing two black and white coloured trailers.
The 35 year old Waterloo man driving the van received life threatening injuries and was taken to Bunbury Regional Hospital where he died a short time later.
The 51 year old male driver of the prime mover was uninjured.
Meanwhile a second person died this morning after two cars collided on South Western Highway near Bunbury
Main Roads have temporarily closed down the stretch of highway in both directions between Dodson Road and Robertson Drive in Glen Iris.
One person is confirmed dead, a second has sustained serious injuries.
The death toll for south west roads now sits at 20 with more than 140 people killed on WA roads between 2012 and 2016.
Earlier this month Road Safety Minister Michelle Roberts said south-west drivers need to show care and consideration for each other on the roads during the festive season.
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