WASHINGTON, Nov 20 (Reuters) - The National

Transportation Safety Board said Thursday it has found evidence

of fatigue cracks in a key part in a crashed UPS MD-11 cargo jet

that killed 14 people in Louisville, Kentucky.

The bulk of the left engine pylon, a structural component

connecting the aircraft engine to the wing or fuselage, was

still attached to the left engine when it separated from the

wing. The NTSB said it found evidence of fatigue cracks in the

left pylon aft mount lug. The Federal Aviation Administration on

Nov. 8 prohibiting MD-11 planes from flying as work continues to

establish new engine inspection procedures.