As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT A/I DUCT WARNING MSG WAS DISPLAYED AT CRUISE ALTITUDE OF FL280 FROM BDL TO ORD. FOLLOWED QRH AND SELECTED WING A/I TO OFF POSITION THEN GOT A L BLEED DUCT WARNING MSG. WHEN A/C CLOSED BLEED VALVES, OPENED RAM AIR VALVE AND DESCENDED TO FL100. DECLARED EMERGENCY AND DIVERTED. DTW MX C/W OPS CHECK OF AILC, OPS CHECK GOOD.