As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB UPON FLAP RETRACTION, THE NR 8 LEADING EDGE SLAT REMAINED EXTENDED. JETTISONED 12,000 LBS OF FUEL AND RETURNED TO DTW. FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE DETERMINED NR 8 SLAT ACTUATOR DOOR TO BE CAUSE, ITEM DEFERRED.