As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 9994, NR 4 ENGINE ROLLBACK AT FL280 DESCENDED TO FL 200 ENGINE RESTARED NORMAL AND RAN NORMAL THE REST OF THE TRIP WITH NORMAL INDICATIONS. INSPECTED NR 4 ENGINE INTAKE AND EXHAUST NO DEFECTS NOTED. FOUND CDP LINE LOOSE RESECURED LINE IAW CFM 56 MM 71-00-00, 73-21-10. PERFORMED MPA RUN NR 4 ENGINE. OP CHECKED NORMAL IAW JRH 13.3. AIRCRAFT WAS GROUNDED.