As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW CREW REPORTED LT AFT ENTRY DOOR EICAS MSG & ENTRY DOORS OVERHEAD LIGHT ILLUMINATED ALONG WITH LOSS OF PRESSURIZATION. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. FOUND LOWER GATE OUT OF RIG. RE-RIGGED LT NR 4 DOOR LOWER GATE. SYS GND CHECKED NORMAL, OPERATION CLOSED.