Soldato
It's not hard to see how the estimate of 400+ residents is reached. There's some information on the building here:
https://www.theguardian.com/uk-news...ed-at-grenfell-tower-london-fire-visual-guide
20 floors with same layout - four 2-bed flats and two 1-bed flats per floor.
Given the pressure on housing in London, 2 persons per bedroom as an average isn't unlikely, so that gets you to 400 straight away. Then there's probably some flats with higher occupancy to take that figure higher.
The travel distance on those plans from front door to what would be deemed the safe area of the stairwell isn't considerable at all. The zone between front door and stairwell would be expected to contain smoke but the exit should be illuminated. There's reports of smoke within the stairwell also because the mechanical venting system failed to activate due to the failure of the alarm.
Fatalities up 12 now, the Fire officers have now been to all floors.