A weatherboard house in Unanderra was gutted by fire on Wednesday night and there were fears someone was trapped inside.
Six fire trucks carrying at least 30 firefighters responded to the first of many calls at 9.10pm.
On the way to the scene crews determined they would be facing a well-developed fire with flames shooting through the roof.
The initial Triple 0 call said there was one person trapped inside the building.
But when crews arrived they found the resident had left the building and was standing on the roadside.
Fire and Rescue NSW Inspector Greg Houston said the fire was so severe that crews moved into “defensive” mode, which involved protecting neighbouring houses.
The fire was finally extinguished by 11pm and the house had been destroyed by fire, smoke and water.