An investigation has found a pilot having a cigarette in the cockpit is what brought an EgyptAir plane down six years ago, killing everyone on board.
EgyptAir flight MS804 crashed into the Mediterranean Sea between Crete and the coast of northern Egypt in May 2016, killing 66 passengers and crew.
The plane had been flying from Paris to Cairo, and Egyptian authorities at the time claimed terrorism had been responsible for the incident.
But an investigation has found that a fire broke out in the cockpit of the plane due to the oxygen escaping from the co-pilot's mask when it is believed smoking was taking place.
The cigarette causing the oxygen to combust.
Three days before the fatal crash, the pilot's mask was replaced and its setting was left on 'emergency' instead of 'normal' by a maintenance engineer, causing the oxygen to be emitted.
According to the investigation's report, Egyptian pilots would smoke regularly on board. Just two months earlier, ashtrays in the cockpit of the same aircraft needed to be replaced.