As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED PRESSURIZATION FLOW LIGHT ILLUMINATED ON CLIMBOUT AND SINGLE PACK OPERATION WOULD NOT PRESSURIZE AIRCRAFT. ACCOMPLISHED PRESSURE FLOW LIGHT QRH. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. RECONNECTED RIGHT PACK SUPPLY DUCT THAT WAS DISCONNECTED. SYSTEM GROUND CHECK NORMAL OPERATION.