The two engines on the Air India flight shut down within one second of each other before the Boeing 787 Dreamliner crashed last month in Ahmedabad, India, killing at least 260 people, according to a preliminary report released Friday.

There were 242 people on board, including 12 crew members. While only one passenger survived, many people on the ground also lost their lives, bringing the total death toll to 260.

A preliminary report released on Saturday has found that fuel-control switches were cut, but does not explain why.