A three-year-old boy died and his dad, 51, is fighting for his life after he tried to rescue his son when a fire tore through their family home.
The boy's mum, 39, and sister, 13, were also taken to hospital and treated for smoke inhalation after the horror blaze in Swansea, Wales, yesterday afternoon.
Neighbours say the blaze is "every parents worst nightmare" as the boy was trapped in the house in West Cross at around 1.20pm on Saturday.
The boy hasn't been named but locals say he had recently started the local Whitestone Primary school.
Family friend Claire Mitchell said: "They lost everything they held dear when the devastating fire engulfed their home.
"The flames claimed not only their possessions but also tragically took the life of their beloved little boy. The father is currently battling for his life in the hospital."
Ambulances took three people to Morriston Hospital in Swansea.
Police said an investigation was being carried out to establish the exact circumstances of the fire which was contained to one house.
Det Insp Carl Price of South Wales Police said: "Our thoughts are with the family and friends of the child who has tragically died at a house fire in West Cross, Swansea."
An online fund for the family raised more than £10,000 within hours of the blaze which broke out after 1pm on Saturday afternoon.
It said: "In times like these, it is our duty as a community to come together and support those who have faced unimaginable losses.
Every donation, no matter how small, will make a significant difference in their lives.
Local councillor Rebecca Fogarty said: "My heart absolutely goes out to the family after such a tragedy.
"I would also like to thank the emergency services and members of the community who have already rallied around. I'm not surprised at how much was raised because the community is very strong and close up in West Cross.
"It's everybody's worst nightmare losing a child. Where the incident has taken place there are families who have lived there for generations and there is a real sense of people pulling together when things like this happen."
A report will be compiled for the coroner and specialist fire investigators are due at the terraced property.
