The resulting scene of the devastation resembled a bomb site and in some senses it was. It was in effect a bomb that you created and detonated.
As a result of your reckless actions you have caused the death of Jamie. You have taken away his life and a large part of his parents and siblings' lives.
The judge accepted it appeared that Partington had a change of heart in blowing up the house when he woke up the next day but said lighting a cigarette was "highly reckless".
"You were aware of the risk but you chose unreasonably to take that risk."
More top news
The Duke and Duchess of Cambridge met young people who have battled mental health issues on Saturday.
Former Chancellor Lord Geoffrey Howe was Margaret Thatcher's longest-serving Cabinet minister, also taking on the role of Foreign Secretary.
Lord Geoffrey Howe is known by many for his resignation speech which was seen as the catalyst which destroyed Margaret Thatcher.