Simplify the following text for a Grade 8 native English-speaking person.
Original: Meanwhile , the dispatcher at Dahlerau , who tried to hold back the departing locomotive by running along the passing train and giving emergency signals , but failed to get the driver 's attention , had tried to reach the dispatcher in Wuppertal-Beyenburg by telephone to hold back the passenger train .
Simplified: The dispatcher had seen what happened and tried to hold the train back with emergency signals , but he failed and the train disappeared behind a curve . He went into his office to call the station in Wuppertal-Beyenburg , but the passenger train had already left Beyenburg .