A report by fire safety engineer Barbara Lane
found that a little over 30 minutes after the first emergency calls were made early on June 14, the fire service's "stay put" strategy had "effectively failed."
Britain uses a passive strategy during fires
, which means people are typically advised to stay in their apartments when there is a blaze elsewhere in the building, as firefighters try to contain the flames.
Seventy-two people died after fire broke out in the West London tower block in what became the deadliest fire in the United Kingdom since 1988.
Residents initially were told by emergency services to stay put inside their flats, only to be told to evacuate almost two hours after the first emergency call, as firefighters struggled to stop the blaze racing up the facade of the building.
However, Lane said, there was "an early need for a total evacuation of Grenfell Tower."
But she also conceded: "I do not wish to imply this was an easy decision to make during the unfolding and complex events that occurred."
In her report, Lane highlighted a "culture of non-compliance at Grenfell Tower." Among her findings were:
-- Cladding was "non-compliant" with building regulations and produced toxic smoke that impeded firefighters.
-- Firefighters "were unable to control the fireman's lift," which caused a short delay to arriving at the initial site of the blaze.
-- Stairway fire doors had not been replaced since 1972 and did not meet current benchmarks.
-- All flat entrance doors were noncompliant with fire-safety regulations, including more than 100 that had been replaced in 2011.
-- Firefighters were unable to get enough water up to the higher levels of the 24-story building, partly because the building was fitted with a noncompliant dry main, rather than a regulation-required wet main that could have provided more water.
-- The ventilation system "did not operate as intended."
The inquiry was shown a video taken by members of the public showing how quickly the fire spread throughout the building.
"The type of materials and how they were arranged around windows in the kitchen, contributed to the speed at which the fire spread from the flat of fire origin to a multistory external fire," said Lane.
Lane added that she had "found no evidence" that design or construction teams had investigated the fire performance of the cladding before it was installed during a refurbishment between 2012 and 2016.
Heartbreaking tales from families
The inquiry, chaired by retired judge Sir Martin Moore-Bick, is tasked with establishing what happened at Grenfell and making recommendations to prevent a similar fire from causing such devastation again.
It opened late last month with heart-rending tributes from bereaved families
who lost loved ones.
They included Marcio Gomes, who told of the devastation of losing his unborn son hours after he and his family escaped the inferno.
His pregnant wife, Andreia Gomes, was put in an induced coma after the couple and their two young daughters ran from the 21st floor of the building at four in the morning. She gave birth hours later to a stillborn baby, whom they named Logan.
Grenfell Tower sits in the affluent London borough of Kensington and Chelsea, but many of its residents were low-income earners living in social housing.