Over 1,400 children in a town in Northern England may have endured sexual abuse that was systematically ignored by police and other authorities from 1997-2013, according to a report released Tuesday.

The independent report, commissioned by the Rotherham Metropolitan Borough Council and compiled by Professor Alexis Jay, found that children as young as 11 were being raped and brutalized in Rotherham since 1997, and had been routinely trafficked to other Northern England towns for sex. The report concluded that at least 1,400 children had been sexually abused during the 16 year time frame, but that this was likely a “conservative estimate of the true scale of the problem.”

The stories relayed in the report suggest that police and other municipal authorities failed to take action against the problem for years, allowing perpetrators to continue to exploit children. One girl who was preparing to testify against her perpetrator received a text message saying that he had her younger sister, and “the choice of what happened next was up to her.” In two cases reviewed by Professor Jay and her team, fathers had tracked down their daughters and tried to rescue them, but were themselves arrested when police arrived on the scene. In some instances, police arrested the victims for drunkenness or disorderly conduct, but let the perpetrators go free. Schools complained that children as young as 11 were being picked up in fancy cars and being taken to meet unknown males, and secondary school heads reported girls being taken away on their lunch breaks to give oral sex before heading back to class.

The report also concluded that until 2007, there was evidence that police believed children as young as 11 were having “consensual” sex with their rapists. While the South Yorkshire Police Department had excellent procedures on the books, officers on the ground through the 1990s failed to implement these practices, and seemed to have very little understanding of the nature of child sexual exploitation.

Council leader Roger Stone, who has served since 2003, said he would step down immediately. “I believe it is only right that as leader I take responsibility for the historic failings described so clearly,” he said, according to the BBC.

Write to Charlotte Alter at charlotte.alter@time.com.