Upon the receipt of proper proofs of the death of a member who has retired on a disability pension or retirement allowance, there shall be paid to the member's beneficiary, an amount equal to one and one-half times the final salary received by the member if such death occurs before the member shall have attained 60 years of age but if such death occurs thereafter, an amount equal to one-fourth of the final salary received by the member.
N.J.S. § 43:6A-20