A cracked part found on a UPS

MD-11 cargo jet that crashed in November in Kentucky was flagged in a Boeing

service letter more than a decade earlier, the National Transportation Safety Board said on Wednesday.

Fifteen people, including three plane crew members, died in the fiery crash at Louisville Airport in an incident that led to the grounding of the MD-11 cargo jet model.

The NTSB said its investigation has found fatigue cracks in a support structure on the left pylon that connects to the wing and the plane’s engine, known as the bearing race.