Residents of the west London apartment block that caught fire yesterday - claiming the lives of at least 12 people - had reportedly raised fire safety concerns for several years.
Twenty people in critical care are among the 74 victims being treated at hospitals across the city, and emergency services are warning the toll could rise, with entire families among those unaccounted for.
Police Commander Stuart Cundy said the recovery operation would be long and complex and the number of fatalities was likely to rise.
The fire broke out in the early hours of the morning yesterday and quickly engulfed the 24-storey Grenfell Tower, on Lancaster West Estate.
It had no sprinkler system, and some residents have said no alarms sounded as the blaze began.
The apartment block underwent a two-year £10m refurbishment as part of a wider transformation of the housing estate, which was completed last year.
Work included new exterior cladding and a communal heating system.
The 24-storey tower, containing about 120 flats, is managed by the Kensington and Chelsea Tenant Management Organisation on behalf of the local council.
Before and during the refurbishment, the Grenfell Action Group claimed that the block constituted a fire risk and residents warned that site access for emergency vehicles was "severely restricted".
In February 2013, the group also warned fire safety equipment had not been tested for 12 months.
It published an extract from a 2012 fire risk assessment that found fire extinguishers in the basement boiler room, lift motor room and ground floor electrical room were more than 12 months out of test date.
Others located in roof level areas had "condemned" written on them in large black writing and had not been tested since 2009.
The tower block was given a medium fire risk rating - defined as a normal fire risk - in 2016 by the London Fire Brigade (LFB) and Kensington and Chelsea Borough Council following the refurbishment.
But residents warned the tower block remained a fire risk. In a further blog posting in November 2016, the action group stated it believed "only a catastrophic event" would bring an end to dangerous living conditions at the tower block.
The group association further alleged residents were given scant information about what to do in the event of a fire.
They claimed "a temporary notice stuck in the lift and one announcement in a recent regeneration newsletter" informed them they should remain in their flats in the event of fire.
"There are not and never have been any instructions posted in the Grenfell Tower notice board or on individual floor as to how residents should act in event of a fire," the blog posting added.
Other London tower blocks checked
Policing and Fire Minister Nick Hurd said checks were now planned on tower blocks that have gone through similar refurbishment.
He said authorities discussed "a process whereby we seek to identify towers that might be in a similar process of refurbishment, run a system of checks and inspections, so that we can as quickly as possible give reassurance to people".
Construction firm Rydon, which carried out the refurbishment, said it was "shocked to hear of the devastating fire" and added that the work "met all required building control, fire regulation and health and safety standards".
In a statement, Kensington and Chelsea Tenant Management Organisation said it was "too early to speculate what caused the fire and contributed to its spread".
Local council leader Nick Paget-Brown said the buildings were regularly inspected, but a "thorough investigation" was needed.
A review of building regulations covering fire safety was promised by Prime Minister Theresa May's chief of staff, Gavin Barwell, last year, when he was a government minister, but has not been published.
Responding to earlier reports, the Department for Communities and Local Government said it was "simply not true" that a report has been "sat on".
Following the Lakanal House fire in south London in 2009, where six people were killed after a fire in a 12-storey building, the coroner recommended the guidance relating to fire safety within the Building Regulations was simplified and the government said this work was "ongoing".
The government also wrote to councils encouraging them to consider retro-fitting sprinklers, as recommended by the coroner, a statement said.
- BBC / RNZ