A 84-year-old man escaped the fire in Northeast Valley, Dunedin, with minor injuries on Sunday afternoon.
The man was rescued by firefighters after failed attempts by members of the public, who tried to save him while explosions erupted from his house about 1pm.
Old televisions and other items were strewn in the front yard of the property yesterday.
The section was cordoned off by Fire and Emergency New Zealand (Fenz).
Fenz specialist fire investigator Catherine Trevathan said yesterday a full investigation into the cause of the fire was not possible.
``The remains of this building are too unsafe to enter to do a comprehensive investigation,'' she said.
``We have been advised by the owner this will be demolished tomorrow.''
North East Valley Normal School is accepting collections to pass on to the man and his wife, who was not at home at the time of the fire.
Principal John McKenzie said parents had already provided cash and food.
``The couple who have it are quite well-known in the community and ... this is a very community-minded suburb,'' he said.
``I think a lot of people will be feeling for the couple at this time and wanting to do something.''
