As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL200 350KTS THE CARGO DOOR INDICATION LIGHT ILLUMINATED. THE FLIGHT ATTENDANT ALSO REPORTED TO THE CAPTAIN THAT THERE IS A LOAD NOISE IN THE CABIN THAT WAS GETTING LOUDER. THE CAPTAIN DECLARED AN EMERGENCY, PROCEEDED TO PHL AND LANDED WITHOUT FURTHER COMPLICATIONS. THERE WAS NO LOSS OF PRESSURIZATION FELT OR OBSERVED.