cairo is one example of Illinoisians getting it wrong, another is Orion up near the Quad cities. Most say o-RI-on, such as in Men in Black. Everyone there says O-ree-on.
As a person born in Texas and raised in Illinois, I still get a slight accent with my relatives. Ya'll are forgettin' another good-un from down there... fixin'
I am fixin' to post a reply, then I am fixin to go finish my laundry.
Take care ya'll