They were awake when the fire started.
It was caused by the dog knocking over an oil burning cook stove, either the stove fuel, or the cooking oil in the pan ignited and the fire spread rapidly in the dry wooden suroundings.
Had they been sleeping it is unlikely that they would have woken in time, though OTOH the stove would not have been lit whilst sleeping, and the dog would have been outside.

In retrospect, the stove should have been fixed down, or even better used outside.
The only lighting was from a 12 volt flourescent light screwed to the wall above the stove, it failed in seconds, presumably the heat broke the glass.

The financial loss was not that great,perhaps a few hundred pounds, but the potential risk to life was great.
They will be a lot more cautious in future.

The dog burnt its front paws, ears, and nose, though not seriously and is expected to make a full recovery.
The owner suffered from minor burns, bruises and small cuts, and has recovered.

Seems to me this is a pretty good example of how questionable practices, often a bit shy of outright error or outrageous risk, line up to allow a major loss.

Among those that might be listed:
1) Fire/evacuation plan was not established and practiced. (This would have influenced 3,4,7 and 10.)
2) Highly flammable temporary structure used for living.
3) No fire extinguisher present.
4) Building has only one exit.
5)Stove of questionable reliability and safety used for cooking.
6)Stove not fastened down or made stable.
7)Most probable source of fire located near the only door.
8) Dog allowed near unsecured source of fire.
9) Sole light source located over most probable location of accidental fire.
10) Reserve light source not readily available.
11) Second source of communications not maintained in safe location.

1) a formal evacuation plan is perhaps going too far
2) Most temporary huts or similar are highly flammable
4) such small buildings normally only have one exit

With the other points, I agree entirely.
WITHOUT the cookstove, the whole idea was very low risk, the owner does not smoke, and no flame based lighting was used in or near.
Had I been staying in such a hut I would have cooked outdoors, and then considered the arrangements acceptable.
I would also have kept basic supplies in the vehicle, and hidden a spare key to this.

The permanent house being built is being made as safe as posible from fire, recent events have concentrated the mind somwhat !

wow that was a near miss.

It always amazes me that caravans have the kitchen right next to the door, in my mind the kitchen should be placed as far away from the door as possible, especially if the dwelling only have one exit.

We can't do what Susan does over here in the UK. We have Millenium burglaries where thieves stick a fishing rod through the letter box
and steel your car keys. Mind you in the states you normally have external mail boxes so I suppose its not such a problem.

Old SOP's die hard for me, my clothes are kept as a pile next to the bed with keys, wallet, mobile and the like kept in the pockets. You never know when the mortar alarms will go off but you can bet its when you are in your deepest sleep. Out of bed into clothes and out the door or window which ever is safest and you have everything with you. Simples!

I think caravans (RV's) have the kitchen right next to the door because the bathroom, living room, sleeping area, etc are all right next to the door Not a lot of flexibility in layout.
I made the comment earlier about the car keys, I see a lot of people have key hooks by their door, or leave them on a coffee table or kitchen counter or wherever. A lot of organizational sites talk about having a landing zone where people come in and drop all their stuff next to the door. I always comment on those that its bad practice, things like keys and phone should be near your bed when your sellping on or your person.

A formal evacuation plan needn't be typed up, notarized, signed in the blood of a virgin, and registered with the UN. I used the word formal to imply that there is something more than a ten second assessment going on. What is needed is a careful and deliberately thought through and realistic plan. It should be talked about and walked through, to the extent practical, with everyone in residence.

A friend failed his first walk-through when she discovered that he window she was planning to jump from was directly above a Spanish Bayonet plant. She had pictured it as being under the next window down. This would have been a jolting discovery finding this out in the middle of a fire. Even worse if she had blindly jumped.

Most small buildings only have one door. But windows and, with a bit of kicking, and a panel that is by design or default weakly attached, it is often practical to have a second exit without resort to either window or door. Figuring out ahead of time where to beat your way through, and possibly removing a few nails or screws, makes it a much more viable alternative.

No need to get obsessive about it but if you spend enough time to sleep in a building spending a couple minutes thinking through the options could save the day when the time comes. It isn't just fire. A tree-falls and tornadoes have been known to trap people. In this day and age of industrial accidents and terrorism having options, knowing where the back door is, makes sense.

When I stay at a hotel I spend a few minutes locating the exits, fire extinguishers. If the path isn't dead simple I have been known to count steps to exits. In a smoke filled hall distances get confused. More than once I've done the same thing in an airliner counting rows of seats.

Also, a fire extinguisher needn't be a high-dollar commercial unit rated and certified. A simple bucket of sand and/or a heavy wool blanket can temporarily smother a fire. Toss it over top of the burning area and it keeps the flames at bay long enough to make an orderly withdrawal. An old garage sale blanket and an old galvanized two gallon bucket with liberated builder's sand can save the day.

A bit after the fact, it might help someone some day, is to remember that even simple wooden structures can be inexpensively whitewashed. This dresses up the exterior and lightens the interior. It also increases the fire resistance of wood. Once the wood catches whitewash won't stop a fire but it can cause the wood to catch and spread fire more slowly. Which buys you time. I've seen a whitewashed piece of wood take most of a minute to catch when thrown into a roaring fire.

Whitewash can be as simple as slaked lime in water, have chalk added to make it whiter, or bought as a commercial product.
http://en.wikipedia.org/wiki/Whitewash