A sea of flowers and candles are placed on the ground outside the Germanwings headquarters at Cologne-Bonn airport

A sea of flowers and candles are placed on the ground outside the Germanwings headquarters at Cologne-Bonn airport March 28, 2015. Andreas Lubitz, the co-pilot who appears to have deliberately crashed Germanwings flight 4U9525 carrying 149 passengers into the French Alps received psychiatric treatment for a “serious depressive episode” six years ago, German tabloid Bild reported on Friday. REUTERS/Wolfgang Rattay