Passengers were trapped on a derailed train for 40 minutes in an accident that has crippled Auckland's busy Britomart Station.
Three carriages derailed as the train was leaving the station, scaring passengers who described the accident as a sudden shake "like a small earthquake".
Trains coming in and out of the station have been suspended indefinitely.
The six-carriage train had 33 people onboard but no one was injured.
Passenger Charles Stewart said everything was going smoothly and then there was a sudden shake "like a small earthquake" as the train came off the tracks.
All the passengers appeared to be unhurt - but were a little annoyed. Many rang work to let their bosses know they would be late, Stewart said.
A big Auckland Transport screen is warning of an "Emergency Service Incident" inside the station, but some people had no idea it meant a train had derailed.
"We thought there might have been a gunman or something," one woman said.
AUT student Kirstin Elphick was on board when the train derailed and felt "absolutely freaked out" when the brakes slammed on.
"It felt like it was going really, really fast. All of a sudden it stopped."
The train looked like it was leaning against the tunnel, Elphick said.
It was "really annoying" that more information was not provided before the passengers got off the carriage, she said, as they had no idea how long they would be there for.
"We were wondering 'what on Earth is going on?'"
Elphick said it was also difficult to hear the announcements over the loud speaker, which only added to the confusion.
An Auckland Council spokesman said the train had derailed at about 9.45am at the platform.
Britomart station will remain closed while people get off the train and the power would be turned off, he said.
Operations could return to normal after the passengers were taken off the train as a spare platform was available, he said.
The spokesman said the train derailed at low speed as it was leaving platform 2, but remained upright.
The passengers would be transferred to replacement bus services but he warned of cancellations and delays.
Scores of people are turning up to find the station still closed.
Auckland Transport staff at each entrance are explaining about the derailed train and directing people to public transport alternatives.
Two pensioners who caught the ferry from Halfmoon Bay hoping to catch the train to Swanson for the day changed their plans when they learned they would need two buses to get there.
"We don't mind too much. We have all day."
AUT law student Levi Farrell was hoping to catch the train home to Glen Eden.
"Now I'll have to catch a few buses. I've never done that before, don't know the routes. I have caught the train every day. I'm not in a hurry so it is not too bad."