As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX - CREW REPORTED EICAS MESSAGE "NOSE AIR/GROUND DISAGREE". EMERGENCY DECLARED FLIGHT RETURNED LAX LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND LEFT NOSE GEAR NOT COMPRESSED SENSOR S10067 DAMAGED. REPLACED SENSOR. SYSTEM GROUND CHECK NORMAL OPERATION.