On the evening of May 27, 1971, shortly after 21:00, a train made up of two
class VT 95 railbuses of the
Deutsche Bundesbahn was running as special service
Eto 42227 (units 795 375 + 995 325) on the single-track line between
Wuppertal-Oberbarmen and Radevormwald, the . The train was filled with senior year pupils of a Radevormwald middle school, their teachers and accompanying railway staff, on the return journey from a class trip to
Bremen. The service was about 30 minutes delayed by the time it left the previous station at Wuppertal-Beyenburg. A regular local freight train,
Ng 16856 (pulled by 212 030, a
DB Class V 100 engine) was approaching Dahlerau station in the opposite direction at this time, so the signalmen at Dahlerau and Beyenburg agreed that the freight should stop at Dahlerau station to let the delayed special pass. In normal operation, the freight train would not stop at Dahlerau. Dahlerau station was equipped with entrance signals, which could show aspects Hp 0 (stop) or Hp 1 (proceed); but it lacked exit signals to control departing trains. In place of exit signals, 'stop' boards were provided at the end of the platform. In absence of any other signal, all trains were obliged to stop at the board to await instructions; the signalman, however, could show a green hand lamp to an approaching train, which allowed its crew to ignore the stop board. This is what would normally have happened to the freight train. The freight train passed the entrance
signal as normal and proceeded slowly into the station, expecting the signalman's instructions. Although not strictly necessary according to the rules, the signalman declared that he showed a red hand lamp to the approaching freight train to make absolutely sure it would stop (according to the rules, the 'stop' board was enough to halt the train). It is unclear what happened next, but the train failed to stop as it was meant to, and departed toward Wuppertal. The driver later claimed that the signalman had displayed a green hand lamp, the signal to pass the 'stop' board. The train trailed the
points already set for the passenger train; the points' seal, which ruptures in such an event, was later found to be missing. About north of the station, on a curve, both trains collided. The motor coach of the two-car special train was compacted to one third of its length and pushed backwards by the freight locomotive, which was five times as heavy and whose front wall (without the driver's cab) was higher than the railbus. The signalman at Dahlerau tried to stop the departing freight train by running alongside it and giving emergency signals, but failed to get the driver's attention. He then immediately telephoned the signalman at Beyenburg to try and stop the passenger train, but it had already left. Neither of the stations nor the trains were equipped with radio, and there were no further signals in between the trains. The signalmen were powerless to stop the trains. Faced with a now-inevitable crash, the Dahlerau signalman phoned the emergency services and told them what was about to happen. Ambulances, firefighters and police were promptly sent from Radevormwald, Wuppertal and Solingen. The rescue effort was hindered by the inaccessibility of the accident site on a hillside and by parents who had waited for the train at Radevormwald station and had now come to search for their children, as well as onlookers who were attracted by the rescue effort. Thanks to quick rescue and medical treatment, 25 people survived despite severe injuries, but 41 pupils, two teachers, a mother and two railway staff died. A single pupil was the only person to escape uninjured. A crisis squad was established at the Radevormwald town hall. Due to the high body count, the dead were laid out in the Bredderstraße gymnasium. Some of the funeral homes that were asked to supply coffins at night time first thought they were receiving prank calls due to the supposed improbability of such a severe accident. ==Cause of the accident==