High Quality Content by WIKIPEDIA articles! The Tangiwai disaster on 24 December 1953 was the worst rail accident in New Zealand. An 11-carriage overnight express from Wellington to Auckland fell into the Whangaehu River at Tangiwai, ten kilometres (six miles) west of Waiouru. The bridge carrying the North Island Main Trunk Railway over the river had been badly damaged just minutes earlier by a lahar from Mount Ruapehu. The KA class steam locomotive, all five second-class carriages, and the leading first-class carriage derailed, resulting in the deaths of 151 of the 285 people aboard the train. Of the 176 second-class passengers aboard, only 28 survived.