The families of four passengers who died on Air India flight 171 that crashed in June have filed a lawsuit in the US against Boeing and aircraft parts maker Honeywell, accusing the companies of negligence.

The lawsuit filed Tuesday said faulty fuel switches caused the accident and accused the companies of doing “nothing” despite being aware of the risks of the aircraft’s design.

Air India Flight 171 bound for London Gatwick, a Boeing 787, crashed shortly after takeoff from Ahmedabad, killing 260 people.

Fuel switches have become a focus for investigators after a preliminary inquiry found that fuel to the engines was cut off moments after the plane left the ground.

The US Federal Aviation Administration (FAA) has said earlier that fuel control switches in Boeing aero planes are safe.

—-Breaking Aviation News