We are David Kirkpatrick and Danny Hakim from The New York Times, and we've been investigating what was behind the fire at Grenfell Tower in London. Ask Us Anything!

Who is likely to be held responsible? Is it the manufacture, Arconic? Or perhaps the contractor?

Hi, this is Danny. It's very early in the process to say definitively where responsibility will fall. The contractor and subcontractors are sure to be scrutinized in the investigations, as well as the role of the tenant management organization that oversaw the building. Arconic is certainly being looked at closely and there has been concern about other buildings with similar cladding. The company has already said it will no longer sell the same kind of cladding to be used on high rises anywhere in the world, as we reported in the link below. The fact that its stock is down about 19% since the fire likely reflects concern in the market over litigation. https://www.nytimes.com/2017/06/26/business/arconic-grenfell-tower-london-fire.html?_r=0

What was the motivation for the council to apply cladding in the first place? What purpose was it supposed to serve?

There had been complaints from tenants about the building losing heat in cold weather, and getting too hot in the summer. The cladding was aimed at mitigating those problems. Cladding systems also can cut energy usage, and can be used to beautify the building, giving it sort of a face lift. That is obviously a sensitive topic when you're talking about public housing in one of the wealthiest parts of the city.

In reporting a story like this, how much do you rely on "leaks" or documents being passed on to you that aren't immediately in the public domain? How do you obtain these documents?

A lot of the documents in this story were in the public domain. Key records included the board minutes of the Kensington Chelsea Tenant Management Organization, which oversaw Grenfell Tower. There were also documents produced by Arconic, the company that makes the cladding panels, that showed how the company recommended it not be used in high rises elsewhere. And there were planning documents from the various contractors that were useful. All of these were public.

Do you think there are factors apart from the cladding which increased the fire spread?

Thanks for the question. There are obviously investigations ongoing that will determine what happened. From what we know so far, the cladding was a factor that was obvious right away to fire safety experts, and it has played a role in high rise fires in other parts of the world. But there is also the issue of the broader design of the refurbishment that was done to the building, including insulation that was under the cladding, and a narrow gap between the cladding and the insulation, as well as potential deficiencies in fire protection measures within the building itself.

So, what was behind the fire at Grenfell Tower in London?

The officials investigations of the fire are ongoing. What we know so far is that there was a faulty Hotpoint refrigerator that was the origin of the fire. The new facade of the building, which was put on last year, appears to have played a major role in allowing the fire to quickly engulf the building. A type of panel, or cladding, was used to resurface the building. The cladding has two thin sheets of aluminum around a flammable core of insulation, and that is seen as a significant factor in what happened. Additionally, there appear to be a number of other factors involved, including the broader design of the refurbished exterior. Grenfell Tower also had only one staircase, lacked fire alarms, sprinklers and a fire escape.

Hi D&D,

Who was the architect of the tower, have you visited any of their other buildings?

Architects will typically reuse details that they become familiar with, by looking at the projects that still stand you may be able to get an idea of the design intent behind this building. They are typically pressured into making projects cost less by the client, but often the drive for aesthetics comes from the themselves.

Good luck with you investigation, i'm interested to read the article when its published.

I live near another building that uses the same contractor and subcontractor and has been evacuated. The cladding there has a similar flammable core material and is being removed. There is a broad review underway of buildings that might have similar problems. Here's a recent story about the testing: https://www.nytimes.com/2017/06/26/world/europe/uk-cladding-test-failed.html

I've heard that a D-Notice has been placed on the press around reporting the number of victims. any truth to this?

I don't know of any official restriction that has been circulated regarding reporting on this subject.