As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 631 - IND-PHX - AT FL280 CRUISE CABIN STARTED CLIMBING RAPIDLY TRIED TO CONTROL AND REQUEST DESCENT TO FL200 MAIN CARGO DOOR LIGHT CAME ON. COMPLETED IRREGULAR CHECK LIST STILL COULD NOT CONTROL CABIN, TURNED BACK FOR ICT, CONTINUED TO DESCEND TO 10,000 FT. HAD TO DUMP FUEL TO MAKE LANDING WEIGHT AND LANDED AT ICT. REMOVED AND REPLACED DOOR OPEN SEQUENCE VALVE. (M)