The quirky clip called Dumb Ways to Die has had nearly 12 million views on YouTube since it was leaked less than a week ago.
The video features animated characters killing themselves in a variety of "dumb" ways.
Leah Waymark from Metro Trains says they are not completely surprised by the popularity of the video.
"[But] you can never predict the speed and the take up, which in this case has been amazing," she said.
Ms Waymark says Metro spoke with their employees about dumb things they have witnessed in and around train stations.
''All our staff were talking to us and complaining about some of the dumb behaviour people exhibit out on our networks," she said.
"So that's really where that evolved from, and we workshopped the best way to reach young people."
The brains behind the clip, John Mescall, says he has been taken back by the response.
He says YouTube has told him it is one of the most successfully shared files on mobile devices.
''From the beginning we planned to make it very shareable, but look you can never plan for something to be the biggest viral campaign in the world," he said.
The song can also be downloaded from iTunes. It has become an unexpected hit in several Asian countries including Taiwan, Vietnam and Singapore.
Ms Waymark says while the popularity of the video has been overwhelming, she says the importance of the message should not be lost.
"To have young people singing about safety around trains is just a terrific outcome for us," she said.