If there was a will, the bank accounts will go to whomever they were willed to, and in the meantime (pre-probate), the executor named in the will has the right to access them and use them for estate expenses or to pay any claims against your grandparents. The executor cannot simply take the money for himself; he manages the estate funds, but only gets whatever share (if any) he is entitled to in the wil.If there was no will, the funds go by "intestate succession"--the rules for who gets what when there is no will. If the only children of your grandparents were your mother and uncle, your uncle gets 1/2, and you and siblings of yours split your mother's 1/2. In the meantime (again, prior to the estate being settled), the administrator or personal representative (either term may be used) appointed by the court for the estate can access the funds for estate expenses or to pay claims against your grandparents or their estate.The executor or administrator/personal representative would need documents (often called "letters testamentary") from the court confirming their authority over the estate; then they can access the accounts.