According to a preliminary report released by French investigators Wednesday, Germanwings pilot Andreas Lubitz had “practiced” the fatal descent that would lead to the crashing of an Airbus A320 and the killing of 149 people on an earlier flight that same day.

Lufthansa announced Tuesday that Andreas Lubitz—the co-pilot of the Germanwings flight that crashed into the French Alps last week, killing all 150 people on board—had previously informed the airline of a "serious depressive episode."