Alone in the cockpit in control of Germanwings Flight 9525, Andreas Lubitz was harboring a potentially lethal secret.
Ignoring instructions from his doctor, who certified him unfit to fly on the day the plane crashed into the French Alps, the 27-year-old appears to have single-mindedly set in motion the chain of events that resulted in the worst air disaster for the low-cost airline and its parent Deutsche Lufthansa AG, killing all 150 people on board.
