The Public Transport Authority says services won't be disrupted despite a fire causing significant damage to the Prospector train.
The train, which runs between Perth and Kalgoorlie, was stationed at a cleaning depot in Kewdale overnight when it caught fire.
It's understood the blaze started in the train's air conditioning and spread to the rest of the carriage.
The PTA says the train can still operate at lesser capacity without the affected carriage.
An investigation is underway to determine how the fire started.