Section 89C. The widow of any employee of a city or town who was killed, or who died from injuries received, or died as the natural and proximate result of undergoing a hazard peculiar to his employment, while in the performance of his duty, and whose death occurred prior to the effective date of any law providing benefits to his widow, shall be paid an annuity in the amount of fifteen hundred dollars so long as she remains unmarried.
This section shall become effective in a city having a Plan E or Plan D charter when accepted by a majority of the members of the city council, and in the case of other cities by vote of the city council, subject to the provisions of its charter, and in a town by a majority vote at an annual town meeting.