‘You just don’t mess or play with a 400-tonne train’, Sydney Trains says as 17-year-old suffers multiple injuries to head, chest and pelvis

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A 17-year-old boy is in a critical condition after falling from the outside of a train on the Sydney Harbour Bridge while he was likely train surfing, NSW police say.

Around 11.30am on Thursday, emergency services were called to the railway corridor between Wynyard and Milsons Point train stations following reports someone had fallen from a northbound Tangara train onto the tracks on the bridge.