After the collision of two S-Bahn trains in the Munich district, the public prosecutor's office is investigating one of the two train drivers.
According to the current status, a train probably ran over a stop signal, investigators said on Thursday in Munich.
The two trains, occupied by 95 people, collided head-on on a single-track route on Monday afternoon during rush hour.
One passenger was killed and 18 people were injured, six of them seriously.
The clean-up work after the S-Bahn accident near Schäftlarn continues at full speed.
The recovery of the two damaged S-Bahn trains is expected to begin on Thursday, Deutsche Bahn announced.
In addition, the public prosecutor and the police want to provide information about the current status of the investigation.
The cause of the accident is still unclear.
Debris was still lying next to the tracks on Wednesday, including torn-out S-Bahn doors, seat upholstery, parts of the side panels and electronics.
The wrecked vehicles are to be recovered with the help of cranes.
In preparation, the contact wire of the overhead line had been dismantled over a length of several hundred meters.
"No signs of technical failure"
However, the weather in Bavaria will be stormy in the next few days;
Experts expect falling trees and falling roof tiles.
It was initially unclear whether this could hinder the work.
The Bavarian Minister of the Interior, Joachim Herrmann (CSU), said on Tuesday: "As things stand at present, there are no indications, no indications that it is a technical failure." The focus is more on whether one of the two train drivers, the train driver, made a mistake could have done.
The public prosecutor emphasized that the investigation would be open-ended.