A quick-thinking neighbour helped rescue six people from their blazing house.
And a smoke alarm probably saved the lives of two children asleep on the top floor of the building, according to firefighters.
More than 20 Havant firefighters tackled the fire in the three-storey house in Park House Farm Way, Leigh Park, last night.
Crew manager Jim Tickner said when they arrived about 10.45pm the house was ‘well alight’ on the first floor.
He said: ‘A member of the public had already helped get four young adults out of the house and a smoke alarm on the top floor woke up two children.’
Seven firefighters wearing breathing apparatus went into the house and rescued the children.
Mr Tickner said three adults were taken to Queen Alexandra Hospital, Cosham, to be treated for the effects of breathing smoke.
They left the scene at 3.30am and he said the cause is still being investigated.