Thought I would recommend this book. It is by a NZ author but the book is set in Australia. Its pretty cool. DD11 got it for her birthday from my sister and gave wanted to read it with me after she had read it (multiple times). We took turns reading a few chapters to each other and then I read the rest on my own in an afternoon. It reminded me a lot of the Tomorrow Series (Tomorrow when the war began etc.) by John Marsden but with a different type of disaster.