75 ILCS 5/4-11

The powers granted boards of trustees shall be suspended during any period that the city, incorporated town, village or township is included within any public library district established under "The Illinois Public Library District Act", as hereafter amended. However, such board shall exercise its powers as to any portion of a city, village, incorporated town or township which is not included within the district.

The board shall, under a court order or law, provide for payment of its liabilities, transfer of its assets to and continuation of library services by the library district within which has been wholly included, a city, or village, or incorporated town or township.