As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT/DAY - FLT 677 - AFTER TAKEOFF, MID-CARGO DOOR WARNING ILLUMINATED. THE AIRCRAFT ALSO STARTED TO DEPRESSURIZE. FLIGHT RETURNED TO PIT WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE MID-CARGO DOOR CLOSED, BUT THE DOOR HANDLE WAS EXTENDED DUE TO WEAK HANDLE SPRING STRUTS. THEY REPLACED THE HANDLE STRUTS. (X)