Gov. Rod Blagojevich Wednesday issued a state disaster declaration for LaSalle, Putnam, Will and Kankakee Counties.
If officials from the Federal Emergency Management Agency find the area meets their requirements, Illinois will be eligible for federal aid.
Bill Burke of the Illinois Emergency Management Agency didn't have an estimate of the damage in cities including Utica Granville, Joliet and Kankakee, but he says it's expected it to be in the millions of dollars.
Eight people, ranging in age from 18 to 81, died in a tavern collapse in Utica and the storm also damaged dozens of homes and businesses.