Greetings from Chicago!
I was lazy last year, sorry i didn't post anything
Rush hour prevent me to catch Rochelle supercell, so i decided to go far up north toward Marengo.
Small tornado near Genoa, with visible wall cloud of that large tornado, which make damage to Rochelle. That thing looked pretty nasty.
Radar images
Official report, with pictures
http://www.weather.gov/lot/15apr09