The person died after the incident at Te Awamutu train stop on Sunday night.
Emergency services had rushed to the Waikato railway station around 6.20pm and said the person had “died at the scene”.
The Waipā District Council said in a Facebook post it was young person that had a “tragic and untimely passing”.
It also shared the details of a vigil to be held at Anchor Park in Te Awamutu on Sunday 11:30am.
“Everyone is welcome to attend and take a moment to remember, reflect and stand together.
“Our thoughts are with the whānau and all those affected at this difficult time.”
A passenger, who RNZ agreed not to name, had said at the time it was something she would never forget.
“We weren’t told what happened, but looking at the trauma of the bystanders… the trauma of staff, something I’ll never forget.”
She said she heard people yelling “stop” as the train left the station before it came to a halt.
The staff were extraordinary, she said, keeping passengers hydrated and informed as much as possible.
Senior Sergeant John McCarthy had previously said police were “providing support to whānau and those who acted immediately to try to help.
“Chief investigator of accidents Louise Cook said following the incident it had appointed a team of investigators who were now gathering evidence.
“Our investigators will focus initially on establishing what happened and identifying any evidence that could assist the inquiry. Our first priority is to gather evidence while it is available.
“That includes examining the train and the scene, and speaking with people who witnessed the accident or were involved.”