A teenage girl lost both her feet after being hit by a train at McIver station in the CBD last night.
The 16-year-old girl is believed to have been crossing the tracks when she was struck at about 11pm.
St John Ambulance took the girl to Royal Perth Hospital under priority conditions.
A police spokesman said the girl was crossing to tracks with a friend near the Moore Street intersection.
She remains in a critical but stable condition this morning.
Public Transport Authority spokeswoman Claire Krol said the PTA will conduct its own investigation into the incident.
Ms Krol it appeared the girl had tried to run across the tracks when she was hit by the train.
She said the incident was a reminder not to “take risks” on the train tracks.