Major Crash officers are looking for witnesses of a fatal traffic crash in Mundaring on Sunday.
At 10.53am a white Toyota Hilux towing a box trailer was travelling east on Phillips Road, Mundaring.
A black Yamaha motorcycle was travelling west on Phillips Road at the same time.
The Toyota turned right into Coppin Road driving into the path of the motorcycle.
The motorcycle collided with the front left hand corner of the Toyota ejecting the rider who landed in the trailer.
The 55 year old male rider of the motorcycle received life threatening injuries and was conveyed to St John of God Hospital in Midland where he was later died.
Major Crash investigators are seeking witnesses who may have seen the Toyota Hilux or Yamaha motorcycle in the Mundaring area around the time.
If you have any information call Crimestoppers on 1800 333 000.