As you are signing the log for this cache take a look around. The bustle of the city, the people from all walks of life...
Imagine in an instant it is all gone. :(
According to this study by Sandia National Laboratories in Livermore, California (a 10 kt nuclear detonation scenario in Chicago) this corner would be the ground zero of a Improvised Nuclear Device placed by terrorists intended to bring the city of Chicago grinding to a halt. Why this corner? I imagine one of the most powerful things that Chicago has going for it might be it's financial district.
Scary! Rumor has it that if they were to take out the Chicago industrial complex it would be further south. I will be researching and placing that cache soon.