On Christmas Eve 1953, 151 passengers lost their lives when a train travelling between Wellington and Auckland derailed into a river in Tangiwai. It is still New Zealand's worst rail disaster.
Tangiwai disaster - this was New Zealand's worst ever rail accident, killing 151 people on 24 December 1953 Photo: New Zealand Railways Corporation collection
This Sunday is the official ceremony to mark the seventieth anniversary of the disaster.
John Mahy was on the train that night, and narrowly avoided being in one of the carriages that fell into the river.
He spoke to Ben Strang.