@greencompass I done a bit of research and it appears that the culprit is the fungal disease Neofusicoccum parvum, colloquially known as the "top-down" disease because it kills the branches at the top of the tree first. This is occurring all along the Perth coastal suburbs. As well as the east coast - Sydney/Brisbane and the rest. Nothing can be done to save the trees. They will all be removed eventually and new ones planted.
