A family of five had to flee their burning home after arsonists are believed to have poured petrol through their letter box and set a fire.
A mum and her four children were only saved thanks to one of her quick thinking sons who spotted the blaze and alerted a neighbour who put the flames out.
The drama unfolded in the early hours of this morning in Windhill Crescent, Mexborough, when three fire engines were called to scene at about 3am.
Firefighters who attended suspect arsonists poured fuel through the front door before throwing a lit object in and fleeing the scene.
A young boy, aged about nine, heard the dog barking and noticed the flames from his bedroom window, and leaped down onto his trampoline in the garden to break his fall.
Firefighters said he alerted a man who lived next door and he shouted for the family to get out before pouring water and damp sheets on the flames.
Nick Abbott, watch manager at Dearne Fire Station, said: “It was a brave thing for the lad to do. We advise people to get out and stay out of house fires and to lower yourself down rather than leap, but this could have been a lot worse had it not been for his actions.
“The dog’s barking also helped to save their lives and so did the actions of the neighbour.
“I have no idea who would do such a thing to a family, I can’t see why someone would have a vendetta against them. We believe at this stage it was caused deliberately and it could have caused a fatality.”
A woman, aged about in her 20s or 30s, and her four young children managed to get out unharmed.
The blaze caused smoke damage to the door and hallway.
Firefighters were due to attend the house today to give fire safety advice and to check on their well-being.
Police attended and were conducting door to door enquiries today as part of their investigation.
Doncaster Police Superintendent Eddie Murphy said: “We will do everything on our power to bring whoever did this to justice.
“Officers have been out speaking to residents straight after the incident and they returned to the scene later today to conduct door to door enquiries.
“We could have been launching a murder inquiry if this had caused a fatality. It is a terrible criminal act.
“I would urge anyone who has information about who might have done this to contact police on 101.”