Two good reasons why this happened.
1: The customer fitted the fire himself
2: He bought the fire and fittings from a well know shed
He is very lucky he and his young family are still here let alone the house and that of the neighbours.
The gas pipe had not been protected passing through the wall and builders opening, Less than twelve months fitted and the gas pipe had perished enough for it to rupture. The gas fire was lit (good knows why in this weather) and fortunately the flame only flashed back to the ruptured pipe, could have been a lot worse had the heat from fire not cleared the flue of an explosive mixture. Five or six hours later his wife noticed the blackening within the fire place," when touched it felt very hot " she said, NO s**t Sherlock. Anyway made safe and returning Thurs to install correctly.
Now this has raised a question. If I am re-fitting an existing fire is this still notifiable