Haw. Rev. Stat. § 88-170: Forfeiture of pension.

Whenever any person who has received a pension from the pension system fails to report oneself for examination for duty (unless excused by the board of trustees), or disobeys the requirements of the board in respect to such examination, or fails to perform such duty as may be required of the person if found able to perform such duty, then the board shall order that the pension allowed and paid to the person shall cease permanently or temporarily.