By Dave Newbart, Lisa Donovan, Lauren Guy and Kara Spak
CHICAGO — Trying to stop a knife-wielding man from killing an elderly man at one of the Loop's busiest corners at midday Thursday, a Chicago Police officer opened fire -- killing the suspect and striking a fellow officer, Police Supt. Jody Weis said.
The friendly fire bullet hit the officer in the vest -- but didn't penetrate, Weis said.
Chicago officers save man held hostage by knife-wielding suspect