Recall please, there was never an instrument approach to CGX. At best an aircraft on an IFR flight plan could execute an approach to MDW (ILS 31) and hope to make it to CGX on a Contact Approach.
I often utilized this accident as an example, when a Air Traffic Controller chose to not issue a Low Altitude Alert (LA) to a pilot. My point was, you don't know what is going on in the cockpit. The pilot might be tying his shoe (a little hyperbole of course) and not notice the aircraft altitude. What would you say at an NTSB Hearing when the Examiner asked you, Mr. Controller clearly the Low Altitude Alert is flashing on your display and blaring in the background on the audio tape, why is it you did not issue the Low Altitude Alert to the pilot and 101 passengers died?