David BaleA house blaze that nearly killed a mother and her three children is being treated as arson - and could have been started by someone putting something through the letterbox.David Bale

A house blaze that nearly killed a mother and her three children is being treated as arson - and could have been started by someone putting something through the letterbox.

The shock conclusion from a Norfolk Fire and Rescue Service investigation comes as a teenage boy involved in saving the lives of his two brothers and mother was hailed the 'unsung hero' in the incident.

Toby Nicholls, 15, dragged his eight-year-old brother from his bedroom into their mother's room and then took control when a neighbour put a wheelie bin up against the wall to rescue the family.

As reported, the blaze swept through the detached house in Windsor Park Gardens, Sprowston, in the early hours of May 6.

The fire service investigated and passed its findings onto Norfolk police, whose spokeswoman said today: 'Investigations are underway and the fire is being treated as arson.'

A source also said that the fire may have been ignited by someone placing an item through the letterbox.

Meanwhile, Toby said he was asleep in the house when the smoke alarm woke him at about 12.30am.

The Sprowston High School pupil said: 'I went to my mum's room and saw that my eight-year-old brother was not there. There was thick smoke.

'I went around to his bedroom and woke him up. I dragged him from the bed and took him to the corridor. It was so hot that I put my hand over his mouth to try and stop him breathing in the smoke.

'I took him to mum's room which has a fire door, which meant we were protected. We put stuff up against the door but the smoke was coming in under it, so we opened the window because we could not breathe.

'Mum was on the phone to the fire service. She was scared and she was shouting for help. I took over the phone and told them what was happening and listened to their advice.'

As reported, neighbour Jeremy Lofts, 36, rushed over to the house and pushed a wheelie bin up against the wall, so the two youngest children could be passed down to him from the upstairs floor.

Fire-fighters then arrived and Toby and his mother were rescued via a ladder.

'I just did what any brother would do, it was just instinct,' Toby said.

The teenager, who is now studying GCSEs, plans to stay on for the sixth form, and then go into performing.

'I would like to be a West End actor,' he added.

His mother said: 'If it were not for Toby, we would not still be around. He saved my eight-year-old son from his bedroom. I could not have got to him. He's the real unsung hero.'

The mother and her children were taken to the Norfolk and Norwich University Hospital suffering from smoke inhalation but were later released.

Do you know someone who deserves to be hailed a hero? Ring reporter David Bale on 01603 772427 or email david.bale2@archant.co.uk.