Police and social workers investigating child sexual exploitation in Manchester knew children were suffering "the most profound abuse... but did not protect them", a report has found.
After a child's death in 2003, police identified at least 97 suspects, but "very few" faced justice, the independent review reported.
The police operation was "prematurely closed down" after officers decided to "remove resources", the report said.
Greater Manchester Mayor Andy Burnham, who commissioned the report as a result of the 2017 BBC documentary The Betrayed Girls, focussed on the death in 2003 of 15-year-old Victoria Agoglia and GMP's subsequent investigation.
He said Victoria's death had "exposed a network...brazenly abusing young people in care... [who] should have been brought to justice but, appallingly, most escaped and some were left to reoffend".
He added there was now "a zero tolerance approach to child sexual exploitation of any kind".
Victoria's grandmother Joan Agoglia said the publication of the report made her feel "wonderful as I've been fighting for this all my life, it seems".
GMP Chief Constable Ian Hopkins apologised for the police failures which allowed the abuse of children in care to continue.
"On behalf of Greater Manchester Police, I want to apologise to all those vulnerable children who were let down in 2004 by police not thoroughly investigating the offences that had been committed against them.
"I want to say that I am personally disgusted that these children were not cared for and by the awful abuse that they suffered."
GMP is reviewing all the cases covered in the report and has made a voluntary referral to the Independent Office for Police Conduct.
Manchester City Council's (MCC) chief executive Joanne Roney said some social work at the time "fell far below the high standards we now expect", adding: "We want to reassure people that, more than a decade and a half of learning later, we are in a much better place."
Victoria Agoglia was in the care of Manchester City Council following the death of her mother.
The report found her carers were aware of her being subjected to "multiple threats, sexual assaults and serious sexual exploitation" and had been told that she was being "injected with heroin by an older Asian man [but] no action was taken by the police or social care".
She subsequently died "having been administered an overdose", but the men who exploited her "have never been brought to justice", the report said, adding that its authors had been denied access to files relating to Victoria by the Manchester coroner.
It said the coroner at her inquest "recognised the multiple concerns", but described Victoria as "having a propensity 'to provide sexual favours'", which "significantly underplays the coercion and control" she was subject to.
In 2004, a 50-year-old man was cleared of her manslaughter, but admitted two offences of injecting her with heroin and was jailed.
After Victoria's death, GMP launched Operation Augusta, which subsequently identified at least 57 children "as potential victims" and up to 97 "persons of interest" involved in the crimes against them.
The report found the operation was ultimately "prematurely closed down... before it could complete its work", a decision that was driven by a desire to "remove the resources", rather than by having "a sound understanding that all lines of inquiry had been successfully completed or exhausted".
"The authorities knew that many [children] were being subjected to the most profound abuse and exploitation but did not protect them from the perpetrators," it said.
The report's authors, childcare expert Malcolm Newsam and former Det Supt Gary Ridgeway, considered a "sample" of cases from Operation Augusta and in each, found that they "cannot offer any assurance" that alleged offences were "appropriately addressed by either GMP or MCC".
They also found eight men identified in the investigation had gone on to commit serious sexual offences, including rapes of girls aged both under and over 16, after the operation was ended and that one suspect vehicle uncovered in the initial investigation was linked to a GMP officer, who was later dismissed from the force.
Former Det Insp Maggie Oliver, who resigned from her job over the way cases in Rochdale were handled by police, said senior officers in GMP had "betrayed the public" and tried to "bury the truth".
Ms Oliver said when she raised concerns at the time, she was met with "misogyny" and described as an "emotional woman" who was "too involved" with victims.
Katie Russell, spokesperson for Rape Crisis England & Wales said:
"This report is by no means the first to conclude children who have been subjected to sexual abuse and exploitation have been completely failed time and again by authorities across the UK.
It exposes pervasive sexist and victim-blaming attitudes, myths and stereotypes at the heart of the criminal justice and social care systems in the very recent past.
And current criminal justice statistics clearly show that victims and survivors of child sexual abuse and all forms of sexual violence continue to be let down today.
We cannot say often or loudly enough: children cannot consent to their own abuse and exploitation. There is no such thing as a 'child prostitute' or a 'sexually promiscuous child', only a child who has been raped and sexually abused.
Authorities should know better. Victims and survivors deserve better. Children deserve better."