As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER NORMAL TAKEOFF AT WEIGHT OF 124K LBS. WHILE PASSING THROUGH ABOUT 4000 FEET. FELT AND HEARD A THUMP, SLIGHT YAW AND LOOKED DOWN TO SEE LEFT ENGINE HAD SPOOLED DOWN. NO EVIDENCE OF VIBRATION OR COMPRESSOR STALLING. WE PERFORMED EMERGENCY CHECKLIST FOR ENGINE FAILURE/DAMAGE DECLARED EMERGENCY AND LANDED WITH NORMAL RESULT. LANDED AT APPROX 122K LBS. DURING DISASSEMBLY, FOUND HPT SHAFT SHEARED.