Police are questioning a 14-year-old boy over a suspected arson attack at a house in Barnsley in which a teenager died and five other people were hurt.
Neighbours said a woman escaped the fire by jumping from a window
The teenager, who is believed to be 15, died from smoke inhalation in the fire at a house in Kitchin Road, Wombwell, on Friday morning.
Five members of a family, including a 12-year-old girl, were rescued from the house and taken to hospital.
South Yorkshire Police have appealed for witnesses to come forward.
A police spokesman said a 44-year-old woman was being treated in hospital for serious burns.
The other injured family members, a girl of 12, and two men aged 20 and 23, are being treated for burns and the effects of breathing in smoke. The 20-year-old man also has two broken ankles.
An 18-year-old woman was released from hospital after treatment.
A neighbour told BBC Radio Sheffield she was woken by "screaming, shouting and banging" coming from the burning house.
"I ran downstairs in my nightie and looked down the street.
"By the time I got down everything was ablaze. I feel absolutely sick, it is just a total shock waking up to see all this happening. It's horrible."