As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, AN APU FIRE WARNING INDICATION APPEARED ON EICAS WITH APU FIRE BELL AND LIGHT IN HANDLE. DISCHARGED APU FIRE BOTTLE AND APU FIRE WARNING CONTINUED. AIRCRAFT DIVERTED TO MSP AND LANDED WITHOUT INCIDENT. APU FIRE SYSTEM DEFERRED AND SPECIFIC PART CAUSING PROBLEM PENDING FURTHER INVESTIGATION.