Dystopian movie or TV series possibly on Netflix in the Past

I am looking for a Dystopian movie or TV Series that starts off with a girl going to visit her family in Australia, I believe. Soon after something happens and civilization falls and they have to fend for themselves.  They start off by going to a grocery store and are attacked by a group of people claiming everything is theirs.  The girl and her family eventually find out that the group is has an entire warehouse of food and supplies which they are guarding.  That is all that I can remember.  I would love to see it again but cannot remember its name.  Thank you for your help!!