Gabrielle Joseph, a 16 year-old model, killed herself after a boy cancelled their date, an inquest heard on Tuesday.
The distraught teenager sent her friends a three-page suicide note on Facebook hours before throwing herself in front of a train on Easter Monday this year.
A text had come through cancelling a cinema date, less than two hours later she was dead. She had told a friend over Facebook, "I am going to kill myself tonight".
She died on the tracks at around 9.30pm near her home in Briton Ferry, South Wales.
The A Level student was an aspiring model, who had already worked for the popular label, Hollister.
Her family said after the hearing that they were "devastated by the loss of our precious Gabrielle".
They encouraged people to look for the signs of teenage depression: "We would like to take this opportunity to urge young people to share their problems by talking to someone they trust."
A family member reflected at her funeral that "Gabrielle tried to deal with things on her own".
The jury in Swansea returned a verdict of suicide.
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