Children will no longer be sent to a young offender institution in west London after an “extraordinary” plunge in safety, it has been announced.
An inspection found soaring levels of violence and self-harm, high use of staff force, poor care and long periods of lock-up in cells at HM YOI Feltham A, which holds teenagers between 15 and 18.
Chief Inspector of Prisons Peter Clarke put Justice Secretary David Gauke on notice to explain how conditions will be improved.
Responding to the report, Justice Minister Edward Argar said: "We have taken the decision to stop placing young people there temporarily."
An inspection report released last month found violence and self-harm had surged at Feltham A following an unannounced check in January.
And a full inspection last week found safety had plummeted even further over the last six months, with a 45 per cent rise in violent incidents since January despite a fall in the number of children held - from 148 down to 108.
The number of assaults against staff, including some described as "very serious", soared by around 150 per cent, while levels of self-harm tripled and were 14 times higher than in 2017.
Some 74 per cent of children reported they had been physically restrained at Feltham A, while 40 per cent said they had felt unsafe at some point during their stay.
A third of children said they were out of their cells for fewer than two hours on weekdays, with the figure rising to nearly three quarters at the weekend.
"We found that in the six months since the last inspection there had been what can only be described as a collapse in performance and outcomes for the children being held in Feltham A," Mr Clarke wrote in a letter to Mr Gauke under the urgent notification process.
"The speed of this decline has been extraordinary."
It is the sixth time the scheme has been used since being introduced in November last year and the first time for a young offender institution.
The urgent notification process allows the chief inspector to inform the Government of any urgent and severe prison problems found during an inspection.
The Justice Secretary then has 28 days to publicly report on improvement measures adopted at the jail in question.
Mr Clarke wrote: "I do not for one moment underestimate the challenges facing the leaders and staff at HM YOI Feltham A.
"During recent months they have often faced violence, some of it very serious. The atmosphere feels tense, and I could sense that many staff were anxious.
"Some were clearly frustrated about the situation in which they found themselves. They wanted to do their best for the children in their care."
Feltham YOI comprises a facility for young adult prisoners, and a children's unit, Feltham A, which holds males aged 15 to 18. The urgent notification only relates to Feltham A.
Mr Argar described the report as "deeply disappointing and concerning" and said much quicker progress needs to be made to ensure a safe environment.
He said: "Therefore, as an immediate response and in addition to work already under way, we have taken the decision to stop placing young people there temporarily to provide space for staff to make improvements and have appointed additional, experienced management staff to support the existing team.
"Refurbishment is also taking place and, this week, we will conduct a review to ensure all cell bells are effective.
"The Governor, who is still relatively new in post, is working hard to drive improvement in an establishment which has one of the highest and most concentrated proportions of violent offenders in the country.
"I know she and her team are incredibly dedicated to turning Feltham A around and we will respond with a formal action plan within 28 days."
Shadow justice secretary Richard Burgon added: "An urgent notification being used for the first time in the youth estate highlights how the Tories are still overseeing a dangerous collapse in safety for young people in custody.
"This situation cannot be allowed to continue - children must not be held in unsafe conditions.
"Whoever takes over as Justice Secretary this week must go beyond the empty rhetoric that is the hallmark of this Tory Government and finally make the safety of young people in custody an urgent priority."
Additional reporting by Press Association.
