Seven-year-old Joshua Prince was killed after being trapped inside a burning house in Khayelitsha, while his father, Joseph Prince, sustained serious burn wounds.
Joshua’s mother, Viwe Zweni, and his brother Junior, 12, survived the fiery ordeal.
The City’s Fire and Rescue Services spokesperson, Theo Layne, said the cause of the fire was being investigated.
Zweni said she had gone to the South African Social Security Agency (Sassa) offices at about 5am to renew the children's social grant documents.
She said she locked the children and their father inside the house and threw the keys through the burglar gates.
“We have one key and we throw it through the burglar gates so that no other people can find it; there is nothing unusual about that,” she
said.
When she returned home, she saw billowing smoke covering her home. She rushed there, but it was too late.
“There were lots of people trying to kick the door open but there was nothing anyone could do, because the flames of the fire were too high,” she said.
“We were a happy family. What happened is sad and losing my child under those circumstances is very unfortunate,” said Zweni.
The incident happened hours after two toddlers, 1-year-old Zahrah and 5-year-old Ziyaad, died when a fire broke out inside their home on Tuesday.
They were trapped in their third-floor flat in Chestnut Way as residents tried in vain to rescue them.
Police spokesperson FC van Wyk said a police officer also sustained light injuries to his face and arm while trying to assist the children.
Van Wyk said an inquest docket was opened for investigation and the cause of the fire was unknown.
Community leader Samiyah Mohamed said: “What happened is very tragic. It is in these difficult times that community members should provide their support.”
Anyone wishing to donate can contact her on 071 524 6471.