As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN TO RAMP DUE TO INABILITY TO SHUT DOWN APU. FOUND PORTIONS OF N1 HAD EXITED DOWN PASSED APU AIR INLET BOOT AT CLAMPS, SLICED THRU APU PRESSURE OIL LINE AND THEN BECAME LODGED INTO APU COMPARTMENT ACCESS DOOR. APU REF WRI 52-40 2307 FOR THE APU ACCESS DOOR REPAIR. REMOVED AND REPLACED APU REF AMM 49-00-00-4.