The train was slowing to a stop when it crashed into a buffer at the end of the line at Richmond station in the morning, the BBC reported.
A 21-year-old man suffered a broken leg and another 15 people were treated for minor injuries, paramedics said.
Police said they were investigating why the train did not stop.
"These people are very lucky -- it was chaos -- things could have been much, much worse," said one of the paramedics.
Sydney Trains Chief Executive Howard Collins told reporters the train had "hit the buffers pretty hard", but had not derailed.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
