The steel doors of the Schuster Line were ordered closed on 10 May 1940 at 03:15, following movements of German troops on the east side of the border rivers Our, Sauer and Mosel. In the meantime, German special forces dressed as civilians and supported by Germans living in Luxembourg - the so-called Stoßtrupp Lützelburg - tried to sabotage radio broadcasting and the barricades along the German-Luxembourgish border but their attempt failed. The Royal Family was evacuated from its residence in Colmar-Berg to the Grand Ducal palace in Luxembourg City.