Notwithstanding anything to the contrary in N.H. Rev. Stat. § 102:16 or elsewhere in this chapter, if a member dies in service while eligible for service retirement under the provisions of N.H. Rev. Stat. § 102:13, in lieu of the return of his accumulated contributions there shall be payable to his designated beneficiary a retirement allowance equal to the allowance which would have been payable to such beneficiary had the member retired just prior to death and elected option 1 as set forth in N.H. Rev. Stat. § 102:16 in favor of such beneficiary. No benefit shall be payable under this paragraph if a benefit is payable under N.H. Rev. Stat. § 102:17.