The house goes from ignoring the fact that its humans are no longer there to frantically trying to save itself.
There are no living beings in most of the story. The closest we come is a dog that drags itself into the house barely alive, and then dies. The people have turned into silhouettes of white paint against the burned-black house.
The five spots of paint—the man, the woman, the children, the ball—remained. The rest was a thin charcoaled layer.
Although there may be no living beings in most of the story, there are plenty of mechanical ones. The house itself is fully automated. It functions in a completely self-sufficient way, and takes care of the humans too. It cooks them breakfast and cleans up after them. It even reads them bedtime poems.
The house is described as dying. It lights a cigar for the man, who is now a spot of paint. Instead of being smoked and put out, the cigar ignites a fire that threatens the house.
"Fire!" screamed a voice. The house lights flashed, water pumps shot water from the ceilings. But the solvent spread on the linoleum, licking, eating, under the kitchen door, while the voices took it up in chorus: "Fire, fire, fire!" The house tried to save itself.
The house is described with anthropomorphism, reinforcing the idea that it is in fact the main character. The house goes from blissful ignorance to acknowledgement of a full-fledged threat. The little robots are not able to save it. It does not have enough water to put out the fire. As much as it tries, the house is destroyed. Nature takes back the land, and all traces of humanity are gone.