R.I. Gen. Laws § 36-10-24: Person to whom death benefit payable.

The payment of contributions of the member and the death benefit to a member or retired member under the provisions of §§ 36-10-21 — 36-10-23 shall be made to such person as the member shall have nominated by written designation duly executed and filed with the retirement board, or if the member has filed no nomination, or if the person so nominated has died, then to the estate of the deceased member.