Is there an Estate if the decedent had nothing but insurance?

My Aunt was on Medicaid, in a nursing home, and died without a will. Now I find out there is a Group Insurance policy with no beneficiary. She is survived only by 2 nieces and 2 nephews. I have handled all of her affairs with Power of Attorney while she was alive but now have nothing in writing to allow me to take any action. What do I do?