The health minister said the failures would not happen again Jersey authorities failed to protect three children from physical, sexual and emotional abuse over a 12-year period, a review has found.
The report, by the Jersey Child Protection Committee (JCPC), found there were serious failings in the quality of care from the authorities.
It said there was no clear protection plan and important information was not shared between agencies.
The health and social services minister has apologised to the family.
The serious case review is the first of its kind in the island.
It looked at the quality of service a child, known only as BA, and two siblings, received from various States departments between 1996 and 2008.
It identified a number of failings in various agencies, including Children's Services, Health and Social Services and the Law Officer's Department.
I are determined to do all we possibly can to make sure something like this doesn't happen again
Deputy Anne Pryke, Health Minister
Independent chair of the JCPC Mike Taylor, said "Despite 12 years of engagement with this family, until latterly, there was no clear protection plan and no measurable improvement targets."
Too much emphasis had been placed on the risk of sexual abuse and not enough attention paid to possible neglect and emotional abuse, the report also found.
The children's mother was too often viewed as the client rather than the children, it said.
"There was a failure of supervision and management to challenge the conclusions being reached," said Mr Taylor.
'Lack of action'
Because important information was not shared between agencies that worked with the children appropriate action was not taken.
"Any lack of action was not adequately challenged," Mr Taylor added.
The report found the police had not passed on relevant information, the education department had not pursued their concerns fully and the health department had failed to carry out the right assessments.
Advocate Timothy Hanson, the children's lawyer, said: "It reveals that there are many failings across a number of agencies, not merely in the past but currently".
The report noted while significant failings had been identified, there had been major changes in policy and practice during the review period.
'Safe and in care'
Mr Taylor said: "I hope this report will be used constructively to learn important lessons."
Health and Social Service Minister Anne Pryke said: "I want to say sorry to these children and their family."
All three children were now safe and in care, she told BBC Jersey.
"The serious case review shows how things went wrong and my fellow ministers and I are determined to do all we possibly can to make sure something like this doesn't happen again.
"Some of the recommendations of the review have already been implemented," she added.
Last year, the States of Jersey agreed to spend £3.2m improving child protection services.
Jersey agencies 'failed to protect children from abuse'