Des Moines, IA- A security breach at one of the nation's largest health systems has affected hospitals in Des Moines and Omaha. Radio Iowa reports that officials at Chicago-based CommonSpirit Health say an IT security incident happened on Monday. Some MercyOne facilities in central Iowa have been affected. A MercyOne spokesman says some IT systems have been taken offline and that may include electronic health record systems. The Omaha World-Herald reports the Creighton University Medical Center and two other C-H-I hospitals in Omaha have taken steps to respond to the security incident as well. It's unclear how extensive the hack may have been. News reports in other states indicate hospitals in Tennesse and Georgia have rescheduled some surgeries and doctors' appointments.