A brutal attack on two young boys in Edlington, South Yorkshire, last April could have been prevented, according to a report seen by BBC Newsnight.
It identifies multiple failings by nine different agencies and says 31 chances to intervene were missed over 14 years.
Parts of the report by the Children's Safety Board will be published this week, though not the full report.
Two brothers aged 10 and 11 at the time have admitted carrying out the attack and will be sentenced this week.
The report, which was ordered after the attack on an 11-year-old and nine-year-old boy, is the latest serious case review centred around Doncaster, where seven children have died since 2004, despite being on the at risk register.
The report highlights 12 lessons that should have been learnt from previous cases and outlines the events leading up to the Edlington attack.
It spells out how the assault was not only predictable, it was entirely preventable.
Over the course of 14 years, nine agencies had been involved with the brothers' family - between them they missed 31 opportunities to intervene.
The report praises the exceptional commitment of some professionals, but cites a lack of leadership and effective multi-agency working as contributing to the incident.
The attack happened in the rural ponds area outside the former mining community last spring.
Two local boys were lured there by the brothers and subjected to a prolonged assault so serious that some details will never be made public.
One boy was left in a coma after a sink was dropped on his head.
Focus on mother
The brothers had moved to Edlington just three weeks before the attack to live with foster parents.
The report says there was no proper supervision of the placement and no clear plan for the boys' management.
The brothers' family had been known to social services for 14 years.
Their father was violent and their mother could not cope with her seven sons.
Yet the report, which calls for better training of staff in the areas of identifying children at risk, finds that professionals focused on the mother, rather than the needs of her children.
History of violence
It highlights an inability to connect the boys' worsening behaviour to their neglectful family background.
In 2006, aged eight, one of the two boys was excluded from school after threatening staff with a baseball bat.
There was a multi-agency meeting but no action taken.
It went very wrong here. The services were not being properly provided, there was poor leadership
Roger Thomson, Chair of Doncaster Safeguarding Children Board
In November 2007, there were complaints of arson and the killing of ducks at a park - no follow-up action was taken despite legal requirements.
They were treated simply as naughty boys, despite what is described as a "pattern of violent behaviour against other children".
A local choirboy was beaten and kicked in a prolonged assault a week before the April attack.
The brothers were due to be questioned about it by police on the very day they carried out the more serious offence.
Some of the report's main criticisms are directed at Doncaster Council's Children's Services Department, which is blamed for a lack of leadership and accountability.
The service was taken over by a government team last year after a damning assessment by inspectors.
Call for monitoring
"It went very wrong here. The services were not being properly provided, there was poor leadership... Multi-agency working was not as effective as it should be. So it was really a dysfunctional service in Doncaster," Roger Thomson, Chair of Doncaster Safeguarding Children Board, told Newsnight.
The brothers had moved to Edlington three weeks before the attack
The council is reserving comment until the report is published.
The report will make 18 recommendations. Four involve staff training at all levels.
It also calls for better monitoring of children excluded from school and of the use of temporary and agency staff, along with their caseloads.
Doncaster's Children Safeguarding Board, which represents all agencies involved, is responsible for ensuring the report's findings are implemented.
Mr Thompson says the public can finally feel reassured: "I would say that there has been doubts as to whether some children have been safe in Doncaster.
"I'm confident that things are improving and have improved and that children are now safer," he said.
The boys are due to be sentenced in Sheffield this week. For the town it is being seen as a chance finally to move on from an episode they say does not reflect the character of Edlington, but the damaged and violent natures of the two young boys who came to stay there.
Watch Liz MacKean's exclusive report on the failures behind the Edlington attack on Newsnight on Monday 18 January 2010 at 10.30pm on BBC Two, then afterwards on the BBC iPlayer and Newsnight website.
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