Fire fighters were unable to save a house in the Central North Island settlement of Raurimu on Thursay morning.
When Fire Service personnel from Whanganui, Ohakune, National Park, Whakapapa, Owhango, Raetihi and rural fire tankers from Taumaranui arrived at the property, the house was destroyed.
Whanganui Fire Service area manager Gary Ward said he was in Ohakune when the fire was reported.
"We were conducting a training exercise in Ohakune at the time so it meant that there were extra appliances on hand," he said.
Mr Ward said the 80 sqm house was well ablaze and although fire fighters managed to extinguish the flames fairly quickly, they were still damping down hot spots at 3pm.
"I believe there was one person in the house when the fire started and they were alerted by a fire alarm," said Mr Ward.
"It reinforces the message that working smoke alarms save lives."
A witness estimated that the house was about "500 metres off Raurimu Rd" and said a woman in her 50s was outside the house "in a state of shock" being attended to by Fire Service personnel.
Mr Ward said the cause of the fire has not been determined and there would be an investigation.