As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRES/DIV/DE- DIV TO MTY DUE TO CABIN ALTITUDE WARNING. PERFORMED EMERGENCY DESCENT. NO PASSENGER OXYGEN MASKS DEPLOYED. CORRECTIVE ACTION: FOUND A BUILDUP OF DIRT /GREASE ON L1, L2, AND L3 DOOR SEALS/MATING SURFACES AND CLEANED THE SAME. (8/20 MSP) R/R O/H PANEL. C/W NO GO ODI CK OUTS.