A member who becomes incapacitated to perform the duties of his position as the proximate result of bodily injuries sustained or a hazard undergone while in the performance and within the scope of the member's duties, shall receive an occupational disability benefit; provided:
The benefit shall be 75% of the member's final average compensation at date of disability and shall be payable until the first of the following dates occurs:
At the end of the month in which the benefits cease as prescribed in paragraphs (3) or (4) above, if the member is still disabled, he shall become entitled to a retirement annuity and the minimum period of service prescribed for the receipt of such annuity shall be waived.
In the event that a temporary disability benefit has been received, the benefit paid under this Section shall be subject to adjustment by the Board under Section 14-123.1.
The Board shall prescribe rules and regulations governing the filing of claims for occupational disability benefits, and the investigation, control and supervision of such claims.
40 ILCS 5/14-123