Annika Sondenheimer, the captain's wife, was serving as a speaker in the North Rhine-Westphalia state parliament at around 11:30 a.m. when the news broke that a plane had crashed on its way from Barcelona to Düsseldorf. She quickly realized it was the plane her husband was piloting. Around the same time, aviation accident investigators from Germany headed straight to the French Alps to determine the cause of the crash. Police officers also flew helicopters to the difficult-to-access crash site. At an altitude of 1,800 meters, a field of debris lay before them.

No one can explain why an Airbus A320 crashed like that. A frantic search is underway for the voice recorder and the black box. Investigations begin in Düsseldorf – including against the two pilots who were in the cockpit. A technical defect is quickly ruled out. And then, just two days after the crash, it becomes clear: the co-pilot deliberately crashed the plane, having previously excluded the captain from the cockpit.

In Haltern am See, an entire town mourns the students and two teachers who died in the crash. More than two months pass before the remains of the more than 60 German victims are repatriated. The investigation reveals that the co-pilot was mentally ill, and that perhaps this should have been known.

What exactly happened in the plane and the cockpit in the last ten minutes before the crash? Aircraft accident investigators have reconstructed this and are certain: the co-pilot intended to kill himself and the people sitting with him in the plane. But who knew about the 27-year-old's mental health problems? Who could or should have prevented him from being in the cockpit?