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 AND THE AIRCRAFT RETURNED TO LAX DUE TO THE FLIGHT CREW REPORTING THAT SHORTLY AFTER TAKEOFF AN APU FIRE WARNING LIGHT ILLUMINATED. THE FLIGHT CREW ACCOMPLISHED THE PROCPROCEDURE AND LANDED SAFELY AT LAX WITHOUT FURTHER INCIDENT. (OPEN)