Whanganui firefighters worked quickly to extinguish a well-involved fire at a house on Somme Parade in Aramoho on Monday.
The house was left severely damaged after two fire crews were called to the location near Te Ao Hou Marae at 11.15am.
Firefighters remained at the home on Monday afternoon dampening hotspots and a fire investigator was called in to examine the scene.
A witness who did not want to be named said he was driving down the road after carting metal in a nearby forestry block when he saw smoke billowing from the house.
"The whole thing had flames coming out of the main areas. The fire service was here by then so there was nothing we could do," he said.
"It was empty, someone else had already been around and kicked all the doors down."
Assistant area commander Jemal Weston confirmed the occupants of the house were not home at the time.
"The cause is yet to be determined, we're actually still trying to put it out. Once it's fully out we will instigate some investigation of cause," Weston said.
"It's a timely reminder to have working smoke alarms inside your house for that early warning."
The occupants of the house have been informed of the fire.