Can anyone tell me what killed my grapevine?

There is one pic in this bunch to show you it 2 months ago, had just got its leaves back (I’m in Australia so it should be peaking now) and the a disease rapidly killed the whole thing. It’s devastating. I’ve also included 2 x pics of the stems cut, hoping it might give me clues as to what happened. So far google ain’t helping much. I appreciate it.