As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAF INFLIGHT DFW-TUS. CARGO FIRE INDICATION WARNING. FIRE BOTTLE WAS DISCHARGED. EMERGENCY DECLARED FLIGHT DIVERTED MAF LANDED WITHOUT INCIDENT. NO EVIDENCE OF CARGO FIRE OR OVERHEAT DETECTED. AIRCRAFT REMOVED FROM SERVICE. REPLACED AFT CARGO ELECTRONIC UNIT & NR 1 FIRE EXTINGUISHING BOTTLE. SYSTEM GROUND CHECKED NORMAL OPERATION CLOSED.