Sec. 15. DEATH BENEFITS. (a) A death benefit is payable as provided by this section on the death:

(1) of a member of a retirement system that occurs in or in consequence of the performance of the member's duties as an employee or volunteer of the fire department included within the coverage of the retirement system;

(2) of a member of a retirement system for any reason if the member met the applicable length-of-service requirement for service retirement at the time of death; or

(3) of a retiree of a retirement system.

(b) Except as otherwise provided by this section, monthly benefits payable on the death of a member or retiree are:

(1) $100 to an eligible surviving spouse of a member or retiree whose service was not exclusively as a volunteer and $16.67 to an eligible surviving spouse of a member or retiree whose service was exclusively as a volunteer;

(2) if there is an eligible surviving spouse and a minor child, $20 to the guardian of each minor child of a member or retiree whose service was not exclusively as a volunteer and $6 to the guardian of each minor child of a member or retiree whose service was exclusively as a volunteer;

(3) if there is no eligible surviving spouse at the time of death of the member or retiree or if the surviving spouse dies or becomes ineligible to receive benefits during the minority of a surviving child, $40 to the guardian of each minor child of a member or retiree whose service was not exclusively as a volunteer and $12 to the guardian of each minor child whose service was exclusively as a volunteer; and

(4) if there is no eligible surviving spouse or minor child at the time of death of the member or retiree, a total of $100 to one or more surviving dependent parents of a member or retiree whose service was not exclusively as a volunteer and a total of $16.67 to one or more dependent parents of a member or retiree whose service was exclusively as a volunteer.

(c) To be eligible to receive benefits as a surviving spouse under this section, a person must remain unmarried after the death of the member or retiree. To be eligible to receive benefits as a surviving spouse of a deceased retiree, a person also must have married the deceased before the deceased's retirement. To be eligible to receive benefits as a surviving spouse of a deceased member who had terminated employment with or otherwise discontinued service for the fire department, a person also must have married the deceased before the termination or discontinuance.

(d) If a member or retiree for whom death benefits are payable under this section is survived by a child who is totally disabled as a result of physical or mental illness, injury, or retardation, the guardian of the child is entitled to receive for the benefit of the child and the duration of the child's disability any benefit that would be payable to the guardian of a surviving minor child.

(e) A board of trustees established under this Act may, in accordance with Section 7 of this Act:

(1) expand the circumstances under which death benefits become payable; or

(2) determine formulas for computing benefits, classes of permissible beneficiaries, exclusions from payment of benefits for certain causes of death, and other conditions for payment of death benefits.

(f) The vested accrued benefit that an eligible survivor receives under this section as the result of the death of a member or retiree on or before the determination date is subject to the terms established by the retirement system as those terms exist on the determination date.

(g) Notwithstanding any other provision of this Act, a death benefit is not a vested accrued benefit until the member or retiree for whom death benefits are payable dies.