Aviation experts are calling the sudden engine fuel cutoff on an Air India jetliner “absolutely bizarre.” A preliminary report into the crash that killed at least 260 people does not clarify how the fuel control switches were turned off.

The Air India airliner carrying 230 passengers and 12 crew members was on its way to the United Kingdom when it crashed into a building shortly after takeoff on June 12, killing all aboard, except for one survivor, and several people on the ground, according to authorities.