Child sexual abuse involving pupils at Knowl View happened from its early years onwards and continued for 20 years, an independent panel found.
The council-run residential school in Rochdale was set up in 1969 to house boys aged from seven to 16 with a "wide range of needs and adverse experiences" but the Independent Inquiry into Child Sexual Abuse (IICSA) concluded there was little evidence of a homely environment.
IICSA said the institution, where late Liberal MP Cyril Smith (pictured) was a governor, failed in its basic function to keep its children safe from harm and, in particular, safe from sexual harm both within and out the school.
The panel said: "Child sexual abuse involving children from the school occurred from its early years onwards.
"Within the school there was sexual abuse of boys by members of staff, and of younger boys by older ones.
"Sexual exploitation of some boys was also taking place in Rochdale town centre by men paying for sex.
"Some boys were also trafficked to other towns for that purpose."
Although concerns were raised from time to time, the panel said members of staff were "at best complacent and in some instances arguably complicit in the abuse that they knew to be taking place and which was treated as 'normal'".
The panel pointed to an indecent assault of a Knowl View boy in 1984 by a sex offender named Roderick Hilton as an early example of "the school's failure to grapple with a serious incident of child sexual abuse".
In September 1990 Hilton gained access to the school and indecently assaulted at least one boy but apart from interviewing staff there was little evidence it provoked the anxious concern or decisive action needed.
The panel concluded there was no deliberate cover-up by the authorities involved but rather a "careless and wholly inadequate response" to the serious sexual abuse of children.
Former director of social services Ian Davey did not choose to pursue child protection issues involving Knowl View in 1991 which the panel said it found "inexplicable, professionally indefensible and extremely poor judgment".
Several council reports followed but the panel said there appeared to be no urgency on the part of senior education officials to address abuse and "matters at Knowl View were allowed to drift".
IICSA said it heard nothing to confirm there was effective liaison between the departments of education and social services.
Copyright (c) Press Association Ltd. 2018, All Rights Reserved. Picture (c) John Stillwell / PA Wire.