The cause of the fiery crash of a CF-18 fighter jet in Lethbridge, Alta., remains a mystery, as a Department of National Defence investigation has yet to determine what caused the accident.

During an airshow practice on July 23, the jet flown by Capt. Brian Bews lost thrust in its right engine while doing a manoeuvre about 90 metres above the ground.

The plane didn’t respond, and he was forced to eject moments before the CF-18 crashed and exploded into a massive fireball.

Bews was hospitalized and suffered three compressed vertebrae.

“Field examination of the engines did not reveal any anomalies. Both engines were sent to the Quality Engineering and Test Establishment for a detailed inspection,” reads the report from the Directorate of Flight Safety.

Bews told reporters in August that he knew instantly something was wrong.

“It became immediately obvious to me that the jet was not acting like it normally acts,” Bews recalled. “I was not in control of the aircraft anymore.”