620 ILCS 5/27.01

The Department, in addition to the other powers and duties conferred upon it by law, is authorized and directed to supervise and to coordinate within and for the State of Illinois emergency or civil defense measures relating to civil aircraft, airmen, and facilities other than those of air carriers principally engaged in interstate commerce made necessary as a result of any severe storm or other emergency or disaster or as a result of partial or complete mobilization to meet threatened or actual military attack or invasion. Any such supervision and coordination shall be consistent with and in implementation of any statewide plan promulgated by competent State authorities for any such situation.