Tragedy befell London last night, as the 24-story Grenfell Tower near Ladbroke Grove caught fire and burned well into the morning hours. Five local hospitals took in over 50 people suffering from burns, several of which are still in critical conditions, and 6 fatalities have been confirmed so far.

In the blaze’s wake, concerns were raised about the adequacy of fire safety measures such as insulated doors and warning systems throughout London and the UK. But the UK has some of the best fire planning and safety products anywhere in the world, going as far as stipulating what types of construction materials can be used to reduce fire risk. That’s why experts, such as Christopher Miers, an architect and the founder of construction dispute resolution group Probyn Miers, were completely shocked with how fast the fire had spread.

“Nowadays, in the UK, we don’t use materials with this degree of combustibility,” he said for The Guardian.

“They are sandwich panels which are two sheets of aluminium with a core, and the core can be made of different materials. In other parts of the world, in the Middle East and in China, the core material was still being made of combustible plastic product, but that is no longer permitted and has not been permitted in the UK for a long time. The panels are not likely to have a combustible element to them. It’s much more likely that the firespread is not the panels themselves, but it’s more likely to have spread by other means.”

**UPDATE: It seems that residents of the Grenfell Tower in London, which burned down, filed several complaints regarding fire hazards — the complaints were ignored by the owners, and no action was taken. Furthermore, the landlord covered the fire alarms with plastic masks, which caused them to catch fire instantly. Not a single fire alarm rang during the enormous fire, which killed at least 6 people yesterday.**

But what are those “other means,” and how does fire usually behave when confined to a building? Well, Alan Fitzpatrick, an 11-year veteran of the Salem Fire Department in Oregon has a good grasp of both those issues. To help teach fire behavior basics to recruits, Fitzpatrick uses giant burning dollhouses he builds in his spare time — and he luckily uploaded one of his demonstrations to help us better understand the hidden dangers of home fires as well.

I’m going to let him do the brunt of the explaining since he’s obviously more qualified but it’s remarkable just how much difference strong ventilation makes for a blaze.

While Fitzpatrick approaches the issue mostly from a firefighter’s angle, knowing the basics of how a fire starts and grows might just make the difference between life and death in a blaze.

Video credits Salem Fire Department.