The Fire Service in Wellington is worried about asbestos contamination from a house fire in the suburb of Wadestown.
Fire fighters were called to the blaze on Barnard Street at 3pm on Wednesday and say they could have extinguished it more easily if they had been called earlier.
The fire totally engulfed the house and spread to surrounding scrub, forcing evacuations of neighbouring houses and the closure of a road and nearby train line.
Fire crews are continuing to monitor the site to make sure it does not flare up again.
Officers are also worried about contamination from asbestos cladding and are discussing the possibility of demolishing the building with Wellington City Council.
Five investigators are at the scene, but the extent of the damage means it could be difficult to determine the cause of the fire.