A Skywest Canadair CRJ-200 on behalf of American Airlines, registration N866AS performing flight OO-2936/AA-2936 from Chicago O'Hare,IL to Cedar Rapids,IA (USA) with 51 passengers and 3 crew, was climbing out of Chicago when the crew donned their oxygen masks, stopped the climb at 6000 feet reporting cargo smoke and diverted to Chicago DuPage Airport for a safe landing about 10 minutes after departure. The crew requested to turn into the wind after landing, then advised they had been discharging fire agent into the cargo bay and requested fire services to inspect the cargo bay. Following emergency services reporting not seeing any smoke the aircraft continued to the terminal, passengers disembarked normally via stairs. Fire Fighters subsequently reported they could smell smoke.
Passengers reported almost immediately after becoming airborne haze occurred in the cabin, the flight attendant initially attempted to calm them down advising this was only mist, however there was also a clear smell of smoke. Shortly thereafter the passengers noticed the aircraft was maneouvering to land.
The FAA reported the aircraft diverted to DuPage Airport reporting smoke in the cockpit.
The remainder of the flight was cancelled.