40 ILCS 5/4-110
If a firefighter, as the result of sickness, accident or injury incurred in or resulting from the performance of an act of duty or from the cumulative effects of acts of duty, is found, pursuant to Section 4-112, to be physically or mentally permanently disabled for service in the fire department, so as to render necessary his or her being placed on disability pension, the firefighter shall be entitled to a disability pension equal to the greater of (1) 65% of the monthly salary attached to the rank held by him or her in the fire department at the date he or she is removed from the municipality's fire department payroll or (2) the retirement pension that the firefighter would be eligible to receive if he or she retired (but not including any automatic annual increase in that retirement pension). A firefighter shall be considered "on duty" while on any assignment approved by the chief of the fire department, even though away from the municipality he or she serves as a firefighter, if the assignment is related to the fire protection service of the municipality.
Such firefighter shall also be entitled to a child's disability benefit of $20 a month on account of each unmarried child less than 18 years of age and dependent upon the firefighter for support, either the issue of the firefighter or legally adopted by him or her. The total amount of child's disability benefit payable to the firefighter, when added to his or her disability pension, shall not exceed 75% of the amount of salary which the firefighter was receiving at the date of retirement.
Benefits payable on account of a child under this Section shall not be reduced or terminated by reason of the child's attainment of age 18 if he or she is then dependent by reason of a physical or mental disability but shall continue to be paid as long as such dependency continues. Individuals over the age of 18 and adjudged to be disabled persons pursuant to Article XIa of the Probate Act of 1975, except for persons receiving benefits under Article III of the Illinois Public Aid Code, shall be eligible to receive benefits under this Act.
If a firefighter dies while still disabled and receiving a disability pension under this Section, the disability pension shall continue to be paid to the firefighter's survivors in the sequence provided in Section 4-114 . A pension previously granted under Section 4-114 to a survivor of a firefighter who died while receiving a disability pension under this Section shall be deemed to be a continuation of the pension provided under this Section and shall be deemed to be in the nature of worker's compensation payments. The changes to this Section made by this amendatory Act of 1995 are intended to be retroactive and are not limited to persons in service on or after its effective date.
40 ILCS 5/4-110