The train derailed, overturned and collided with the rocky walls of the cutting in a remote area south of the station.

It was reported that the rescuers had to carry heavy lifting equipment for more than 1.5 km (0.93 mi) to reach the site.

[7] The human-factors accident investigator determined the organisational culture had the driver firmly in charge, making it psychologically more difficult for the guard to act.

[7] Tangara trains have a number of safety and vigilance devices installed, such as a deadman's brake, to address problems when the driver becomes incapacitated.

The train in question was a four-car Outer Suburban Tangara set, numbered G7 and fitted with a Mitsubishi Electric alternating current traction system for evaluation purposes.

Neither the deadman's brake nor the guard had intervened in this situation, and this excessive speed was found to be the direct cause of the accident.

Furthermore, the majority of braking and traction system components were thoroughly examined and tested by experts from Australia and overseas, and found to be working normally.

In addition to the deadman handle and foot pedal, the trains are fitted with "task linked vigilance" – which resets a timer every time the driver activates certain controls.

If there is no change in control, a flashing lamp and then buzzer sound and the driver is required to acknowledge a vigilance button.

[citation needed] Such a system had been fitted to G7, but was in the early stage of fleet roll-out, and hence had not been commissioned and switched on at the time of the accident.

Rescue workers who attended the scene were impeded from accessing the trapped passengers on the train because they did not have the keys required to open the emergency exit doors.