After fire spread through Grenfell Tower , reports emerged that residents were advised to stay in their flats in the event of a blaze.
The "stay put" was outlined in a Grenfell Tower Regeneration Newsletter in July 2014, which stated that the building was designed according to "rigorous fire safety standards".
On Wednesday (June 14), pressed on reports that residents had been advised to stay inside their flats in the event of a fire , London mayor Sadiq Khan told BBC Radio 4's Today programme: "Thankfully residents didn't stay in their flats and fled to safety.
"One of the concerns that we have is it's a 24-storey building but for obvious reasons, with the scale of the fire, our experts weren't able to reach all the way to the top, so of course these are questions that need to be answered as soon as possible."
The 2014 Grenfell Tower Regeneration Newsletter stated: "Our longstanding ‘stay put’ policy stays in force until you are told otherwise.
"This means that (unless there is a fire in your flat or in the hallway outside your flat) you should stay inside your flat.
"This is because Grenfell was designed according to rigorous fire safety standards.
"Also, the new front doors for each flat can withstand a fire for up to 30 minutes, which gives plenty of time for the fire brigade to arrive."
Grenfell Tower block fire
A "stay put" states that if a fire breaks out in a flat, the occupants of that flat should evacuate but that occupants of other flats should remain where they are.
It relies on effective "fire separation", or "compartmentation", between flats.
The Local Government Association's (LGA) 2012 publication 'Fire safety in purpose-built blocks of flats' says: "This is the basis for the ‘stay put’ principle: when a fire occurs within one dwelling (or, less likely, in the common parts), it is normally safe for other residents to remain within their own flat.
"This principle is undoubtedly successful in an overwhelming number of fires in blocks of flats. In 2009-2010, of over 8,000 fires in these blocks, only 22 fires necessitated evacuation of more than five people with the assistance of the fire and rescue service."
The LGA report that some authorities had instead adopted a "simultaneous evacuation" policy unless the standard to which the building was constructed had been proven.
It concluded that this was "unduly pessimistic" and "not justified by experience or statistical evidence".
We've set up a JustGiving page in aid of those affected. To donate visit www.justgiving.com/crowdfunding/grenfell-tower-support.
Keep up to date with the latest news in west London via the free getwestlondon app.
You can set up your app to see all the latest news and events from your area, plus receive push notifications for breaking news.
Available to download from the App Store or Google Play for Android .
