As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 3192 - CLIMBING THROUGH 11,000 FEET, THE CARGO DOOR WARNING LIGHTS ILLUMINATED. THE CREW PERFORMED QRH PROCEDURES AND THE CABIN WAS DEPRESSURIZED. THE AIRCRAFT RETURNED TO DTW. MAINTENANCE ADJUSTED THE CARGO DOOR HANDLE POSTION SWITCH. ALL CHECKS SATISFACTORY. (M)