The Australian media have reported 3 different causes to the black-out.
1 - Lightening - which I think they have now ruled out.
2 - An old overgrown tree snagged a main powerlines that was sagging, which caused a cascading effect tripping the safety switches.
3 - My favourite. A yet unknown terrorist group brain washed a squad of squirrels into making a suicide runs onto the major power lines.
