Teen fighting for life after train surfing in Sydney's south in second incident this week

A young boy is fighting for life after falling from a moving train in Sydney's south in the second train surfing accident this week.

The 13-year-old fell from inside the train and landed on the tracks near Engadine, sustaining serious head injuries and being taken to hospital in a critical condition.

Emergency services were called to the scene at the Princes Highway near Heathcote Road about 8.20pm.

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The incident comes after a 13-year-old boy was taken to hospital after a fall while train surfing near Woollahra.

He was among nine other train surfers when he fell and landed on an unused platform.

Sydney Trains chief executive Matthew Longland urged parents to step in before tragedy strikes.

"One slip, they're on the tracks and can tragically lose their lives," he said.

"Please talk to your children, let them know how dangerous this behaviour is."

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NSW Police Minister Yasmin Catley urged young people to think twice before train surfing for a social media post.

"The message is loud and clear, stop this foolish behaviour," Catley said.

"For a post and boast, it's not worth your life."

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