As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: SHORTLY AFTER TURNING OFF LEFT PACK FOR BLEED, THE TRIP NUMBER 1 ENGINE ROLLED BACK WITH ACCOMPANYING THUMPING AND CLUNKING SOUND. WITH ENGINE AT IDLE, ENGINE INDICATIONS WERE NORMAL. WHEN POWER IS ADDED, A CLUNKING SOUND WOULD RETURN. AIRCRAFT AIR INTERRUPTED, BACK TO AND LANDED SAFELY AT DFW. (OPEN).