Except for a retiree who elects an optional form of an allowance under §§ 21-401 and 21-402 of this article, payment of an allowance ends and further rights may not arise from service as a member if:
(1) a member, former member, or retiree dies; and
(2) (i) the member, former member, or retiree leaves no surviving spouse or children under the age of 18 years;
(ii) the surviving spouse dies and there are no children of the member, former member, or retiree, who are under the age of 18 years; or
(iii) the last of any children under the age of 18 years becomes 18 years old or dies before becoming 18 years old.