Falcon Funding v. The City of Elgin 

LLC and City entered into annexation agreement to annex 36 acres at corner of Randall Road and Route 72. Property was never developed, and annexation agreement expired in 2001. LLC filed suit to disconnect property from City's corporate limits. Equitable estoppel can be raised as affirmative defense to disconnection petition. Challenge to sufficiency of affirmative defenses can be response to summary judgment motion, as affirmative defenses first raised in summary judgment motion are not waived by not raising them in answer. Summary judgment properly denied as City failed to adequately plead and establish two elements of estoppel: misrepresentation and knowledge of its falsity. Failure to develop property does not necessarily indicate false representations of intent to develop it.