Dozens of care homes across London have been ordered to improve after failing to achieve even basic fire safety standards, a BBC investigation has learned.
After hospitals, firefighters consider care homes to present the single greatest risk to life of any public buildings. Residents are often elderly, fragile or mentally ill.
But 29 care homes in the city have been discovered not reaching basic standards since 2010.
The London Fire Brigade (LFB) issued each of the homes - many of which were breaching the law - with a legal Enforcement Order, compelling them to make changes.
The homes were guilty of breaches including:
- No fire escape plans
- No training for staff
- No marked fire exits
Green Party London Assembly Member Jenny Jones said: "It is quite horrifying. In care homes you have some of the most vulnerable people in society - people who can't move around quickly. It's crucial those homes have good fire safety procedures.
"This sort of thing should be absolutely basic at places with residents who are not quick on their feet. Fire safety plans, staff training and emergency exits have to be up to date."
Some of the homes had up to eight individual breaches of fire regulations, each potentially lethal.
The importance of clear fire safety plans was underlined by a fire at Rosepark care home in Scotland, which killed 14 people.
An inquiry into the 2004 tragedy, published this April, found "some or all" of the deaths could have been prevented if the home had a decent fire safety plan in place.
A further "serious deficiency" was the "limited attention" given to how residents would escape a fire - the same flaw found at many of the London care homes.
There are 1,976 care homes in London. Some 663 have been checked since 2010 - and enforcement action was taken at 4% of those.
LFB called the rate "unacceptable".
The remaining 1,313 homes may not have been checked for several years.
Ms Jones said: "At the moment fire checks only have to happen every four years. I'd say there's a strong argument for having them more often - particularly in places where there are vulnerable people."
Six of the 29 flawed homes were in the London Borough of Croydon. All are privately run.
And the BBC has learned that last year an elderly woman was killed by fire at one of those homes.
Betty Brittain died in sheltered housing unit Edward Jobson Court, run by Housing21.
The inquest recorded a verdict of accidental death.
But it heard the pensioner had previously burned herself in a similar incident.
And the hearing was also told that, while fire alarms went off in Ms Brittain's flat, they did not go off elsewhere in the complex.
After the fire, LFB found a number of flaws. These included failure to establish an appropriate emergency plan, failure to ensure employees receive adequate safety training and failure to take general fire precautions.
An LFB spokesman said they did not think these flaws contributed to the death - but admitted he could not be 100% sure.
Paul Richards, director of property management at Housing21, said of the death: "For the people who live here and lost a friend, and for the organisation as a whole, it's traumatic.
"It does make you really make sure you've got the systems in place, making sure your systems are really geared up.
"Fundamentally your role as a landlord is to keep people safe. The fire of course focuses the mind on that."
He continued: "It's a fundamental duty to make sure you're not waiting for Enforcement Notices - not waiting for a problem, but being proactive."
The home has made numerous changes on the advice of the LFB.
Steve Turek, assistant commissioner for the London Fire Brigade, said: "It's important for owners of care homes to take their responsibilities seriously.
"I don't think it's acceptable for anyone who receives an Enforcement Notice to say it was for minor infringements.
"We don't issue Enforcement Notices lightly."
He added: "It's important people who are in charge of both care homes and sheltered accommodation understand the importance of their role."
Many of the censured homes had not carried out a legally-required fire risk assessment (FRA) to pinpoint potential dangers.
A 2009 fire at tower block Lakanal House - which did not have an FRA - killed six, and experts say if checks had been done they may have prevented the tragedy.
In light of the tragedy, all council houses must list FRAs on a public register.
Responding to the BBC investigation, Ms Jones demanded a similar system for care homes.
She said: "There's a strong argument for having a public register of care homes so anybody can see if they do have adequate precautions."