A mourning flag flutters in the wind in front of the catholic Sixtus church in Haltern April 1, 2015, during a memorial service for the 16 students and two teachers from the Josef-Koenig-Gymnasium high school in Haltern am See, who were on board the ill-fated Germanwings flight 4U9525 that crashed in a remote snowy area of the French Alps on its way home to Duesseldorf. The co-pilot suspected of deliberately crashing the Germanwings jet told the Lufthansa flight training school about a previous period of depression, Lufthansa said on March 31, 2015. REUTERS/Wolfgang Rattay