The Tangiwai Train Disaster

The Tangiwai disaster was a railway accident that occurred when a railway bridge over the Whangaehu River collapsed beneath an express passenger train at Tangiwai, North Island, New Zealand. The locomotive and the first six carriages derailed into the river, oofing 151 people. The subsequent board of inquiry found that the accident was caused by the failure of the tephra dam holding back nearby Mount Ruapehu's crater lake, creating a rapid mudflow (lahar) in the Whangaehu River which destroyed one of the bridge piers at Tangiwai only minutes before the train reached the bridge. The volcano at Mount Ruapehu was not erupting at the time. The disaster remains New Zealand's worst rail accident.