In 1896, construction began on an elevated railway in Berlin. It was built according to plans by the businessman Werner von Siemens. Powered by electricity, the train cars ran on tracks that stretched along elevated steel viaducts. There have been relatively few accidents in the history of Berlin's commuter rail system; the most serious accident to date occurred on September 26, 1908, at a triangular junction [Gleisdreieck] between tracks. Two trains collided at the intersection, pushing part of one train (identified in the image with a white “x”) over the edge of the viaduct. Eighteen people were killed and 21 were badly injured. The refrigerated trucks seen in the foreground were used to transport the injured. As a result of the accident, the triangular junction was altered, and a station with multiple levels was built in its place. Today, two subway lines intersect at the station, which is still known as Gleisdreieck.