All Auckland trains have stopped dead in their tracks, due to a Kiwirail signal fault.
Services ground to a halt at 11:15am on Friday.
All main terminal stations have been closed until further notice, and it is unknown when services will resume.
All trains which have stopped at platforms are off-loading passengers. Scheduled buses will replace trains.
Passengers on trains between platforms were stranded for over an hour before their trains were moved so they could disembark.
One man told Newshub his wife was trapped on a train between Greenlane and Penrose for over an hour.
"[She] is starting to freak out and is very thirsty. There are no facilities either obviously!"