As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF, PILOT REPORTED 'SMALL EXPLOSION' WITH SPARKS AND 'SMOKE' FROM THE RT ENGINE. SECURED SAME AND RETURNED TO AIRPORT AND MADE UNEVENTFUL SINGLE ENGINE LANDING. MAINTENANCE FOUND N1 SECTION OF ENGINE LOCKED UP. NII SECTION FREE TO ROTATE.