As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL345, CABIN ALTITUDE WARNING HORN SOUNDED. CABIN ALTITUDE CLIMBING AT 500 RPM AND COULD NOT CONTROL MANUALLY. DECLARED AN EMERGENCY AND INITIATED DESCENT TO FL100. PASSENGER OXYGEN MASKS DEPLOYED. MAXIMUM CABIN ALTITUDE WAS 15,000 FT. FLIGHT LANDED AS SCHEDULED WITHOUT FURTHER INCIDENT. DTW MAINTENANCE REPLACED THE AUTO AND MANUAL CONTROLLERS, COALESCER BAG, AND 35 DEGREE TEMPERATURE SENSOR. OPERATIONAL CHECK NORMAL. STATION BUF CHANGED TO LGA.