The U.S. National Transportation Safety Board confirmed on Tuesday that the British Airways Boeing 777-200ER that caught fire during its takeoff roll at Las Vegas McCarran International Airport on September 8 suffered an uncontained engine failure. Examination of the GE90-85B engine revealed that a portion of the stage 8-10 spool in the high-pressure compressor (HPC) section had failed, shedding fragments that breached the engine case and cowling. Investigators recovered more pieces of the HPC spool from inside the engine for metallurgical examination.

The NTSB said it had collected all pieces of the engine’s damaged stage 8 disk rim and found that the fracture started the HPC stage 8 disk web, a part of the stage 8-10 spool. GE continues to perform “high-priority, focused inspections” of HPC hardware from other GE90 engines. The Board added that whatever inspection data it and GE gather will determine any further investigative actions.