The mayor of Auckland is demanding answers after the city's trains were shut down in the middle of rush hour due to a major power outage in Wellington.
The outage at National Train Control hit around 4pm yesterday afternoon.
It lasted for about an hour but caused disruption for much longer as commuters attempted to catch trains home.
Back up systems also failed.
Once signals were restored, commuters faced lengthy delays as trains got moving again.
Len Brown says the problem is disappointing at a time when hundreds of millions of dollars are being spent on upgrading Auckland's rail network.
"We've a got fully integrated electric rail system coming into position mid next year, and we do not want any of these types of control issues impacting on the delivery of super modern service."
Len Brown's expecting a report into what happened on his desk this morning.
Meanwhile KiwiRail has been investigating what caused the power outage.
Chief executive Jim Quinn says it's a very unusual incident which has never happened before.
"We'll investigate this as quickly as we can and run to ground what's both caused the issue and secondly what's meant that the backups didn't kick in."
Photo: NZ Herald