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 DUE TO: LEADING EDGE FLAPS TRANSIT LIGHT ILLUMINATED DURING CLIMB, COULD NOT RESET; AIRCRAFT AIR INTERRUPTED BACK TO AND LANDED SAFELY AT ORD. FAULT CORRELATED TO FAULTY SLAT NUMBER 3 INBOARD PROXIMITY SENSOR #S999. REMOVED AND REPLACED SENSOR. OPERTIONAL CHECK GOOD. PER AMM 27-88-11.