When you die without a Will, the Will cannot be found, or the Will is invalid, a person dies intestate.
If you do not have a Will, one of your beneficiaries would apply for Letters of Administration from the court. Your estate would then be administered under the law relating to intestacy.
Your estate (which also may include some or all of your superannuation benefit), would be distributed according to these intestacy rules. The rules vary from State to State, but generally the distribution is firstly to the spouse and children, and then other next of kin, such as brothers, sisters, parents, etc. Most states now recognise de facto spouses.
If you do not have a Will, we recommend that you consult with your estate planning lawyer immediately to have a Will drafted. Once you have a valid Will in place, we recommend that you review it at least every three years or whenever your circumstances change.