In the night before 12 April 1999, a crew worked on the track of the Wuppertal suspension railway. A steel claw fitted for the work was not removed. The first train of the morning struck it and fell into the river Wupper. Five passengers died, and at least 37 were injured. Before the line was released, three supervisors each had to check on their own that the track was clear. The regional court convicted them. It acquitted five other defendants. It reasoned that each worker could rely on the others, under the Vertrauensgrundsatz, the principle of trust. On 31 January 2002 the Federal Court of Justice overturned four of these acquittals. Where the danger was obvious to everyone working there, a worker had to make sure that his colleagues had done the work given to them.