A preliminary assessment in last month’s disaster focusing on fuel being cut to both engines only deepened the mystery for people grieving loved ones.

Authorities released a preliminary report on the Air India crash, following an investigation. The London-bound flight from Ahmedabad crashed minutes into the June 12 flight. Only one passenger of the 242 passengers and flight crew survived.

Preliminary findings into last month’s Air India plane crash suggest the aircraft’s fuel control switches were turned off, causing a loss of engine thrust shortly after takeoff.