Nearly 500 total severe weather reports (and likely to still grow as more reports are confirmed and finalized) logged by the Storm Prediction Center, the majority across the Chicagoland area. 

A total of 11 tornadoes that we have confirmed in northern IL (including 2 in Ogle County just outside of the immediate Chicago area) and northwest IN on July 15th—there were six total on Sunday so that makes 17 tornadoes in the Chicago National Weather Service forecast area since Sunday. NOTE: This number will increase as the National Weather Service continues its survey work…

Here are details from completed storm surveys on the destructive twisters from NWS Chicago survey teams