The 18-year-old girl posted a desperate blog in an online forum, telling family and friends she was sorry for what she was about to do.

Strangers concerned for the girl's safety then began a frantic mission to track down the girl and her family on Twitter, with users re-posting the blog.

It travelled around Australia and even captured attention of worried social media audiences in the US.

The girl's mother, who cannot be named, was eventually contacted by strangers who described the post as a 'suicide note' and told her to contact police.

"I'm grateful to everyone that chased me down and contacted me," she told 3AW today.

"Through her posting and everyone re-posting it, three people have tracked me down through social media by getting my work details and contacting me at work and basically just asking me if I was her mum.

"I was able to get onto police and tell them where she was."

The mother said police discovered her daughter asleep at her home, and she had come to no harm.

The woman said her daughter has a history of self harm and is now receiving treatment in hospital.

The girl has since thanked the strangers who were looking out for her on the same blog site.

"I'm alive. I'm in hospital. The police came to my house and found me well," she wrote.

"I'm so sorry to the people I worried."

The girl's mother warned that social media has a dark side, but she said on this occasion it had helped to save a life.

"It is bad in some ways, but it does have a good side too."

Readers seeking support and information about suicide prevention can contact Lifeline on 131114 or SANE Helpline on 180018 SANE (7263)

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