As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT THE MAIN CARGO DECK SMOKE LIGHT ILLUMINATED AND FIRE BELL SOUNDED. THE #7 SMOKE DETECTOR WAS ILLUMINATED GREEN. AFTER 10 SECONDS OR SO THE SMOKE WARNING AND HORN STOPPED. SMOKE PANEL THEN NORMAL. CARGO DECK WAS COLD WITH COLD IGLOOS ON BOARD - EMPTIES. FLIGHT NORMAL REST OF FLIGHT. GROUNDED - YES. PERFORMED GVI OF MAIN CARGO DECK; NO SMELL OR OTHER DEFECTS NOTED AT THIS TIME. CONDUCTED MAIN DECK SMOKE DETECTION TEST REF IAW AMM 26-16-07, NO FAULTS NOTED.