As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN THE CREW ATTEMPTED A CROSS BLEED START ON THE NR 1 ENGINE, THE SMOKE AFT LAV WARNING MESSAGE ILLUMINATED AND A FLIGHT ATTENDANT REPORTED FUMES FROM FLOOR VENTS. THE CREW DECLARED AN EMERGENCY AND EVACUATED THE AIRCRAFT. MAINTENANCE FOUND THE RT AIR CYCLE MACHINE TURBINE SEIZED. THE ACM WAS REMOVED & REPLACED IAW CRJ700 AMM 21-51-08-400-801-A01. OPERATIONAL AND LEAK CHECKS WERE GOOD. THE AIRCRAFT WAS THEN RELEASED FOR SERVICE.