Teachers and social care staff did not show enough "professional curiosity" in a girl who died after years of abuse by her aunt, a serious case review said.
Shanay Walker, 7, died from a brain injury at a house in Nottingham in July 2014 while in Kay-Ann Morris's care.
Morris was later cleared of murder after a trial at the city's crown court but jailed for child cruelty along with Shanay's grandmother, Juanila Smikle.
The review concluded Morris had "deceived many professionals".
Shanay was placed in her aunt's care in 2012 after her mother, Leanne Walker, suffered post-natal depression.
The report found in the two years leading up to her death, bruising and injuries sustained by the child were explained away by her aunt as accidental or the result of self-harm.
It echoed a coroner's criticism of Southglade Primary School's child safeguarding arrangements, describing them as "chaotic" and "at times unclear".
Early concerns about injuries and bruising reported by teachers and assistants were held in handwritten records by the assistant head but were destroyed when a new form was introduced.
There was also "considerable tension" within the school's safeguarding team and staff were left feeling "confused" after being reorganised, the report said.
In 2013 Shanay was treated in hospital for a burn to her leg, which her aunt said was caused by her deliberately standing in front of a heater.
The report criticised medical staff for their "uncritical acceptance" of Morris's account and failure to reflect on the likelihood of a six-year-old girl engaging in this type of behaviour.
Chris Cook, chair of the Nottingham City Safeguarding Children Board, said: "Whilst professionals undoubtedly had Shanay's well-being at heart, with the benefit of hindsight it is clear they could have displayed more professional curiosity about issues and incidents which emerged.
"However, as the coroner acknowledged, it remains the case that they could not have predicted the tragic outcome for Shanay.
"We have made recommendations to address issues around identifying and reacting to potential self-harm and non-accidental injuries among children, responding appropriately to other health issues and ensuring that the role of schools in safeguarding children is recognised and reflected in multi-agency practice."
"We are satisfied that appropriate changes are under way or have been implemented and that all agencies would now be more focused on how their collective actions impact and benefit the child."