WEST HARTFORD, Conn. (AP) — An investigation has revealed multiple credible allegations of sexual and physical abuse by former faculty and staff spanning decades at a school for deaf children in Connecticut, school officials said Friday.

The American School for the Deaf in West Hartford released the findings of the investigation one year after it says it learned of allegations from alumni of “inappropriate physical conduct” by former faculty and staff at the school and a summer camp it operates.

The school says it was able to corroborate allegations of sexual misconduct against several former faculty and staff, including a longtime executive director who is accused of sexually abusing a student decades ago.

Nearly 40 alumni also reported “persistent” corporal punishment and physical abuse from the 1960s through at least the 1980s, the report said. Students said they were forced to kneel on broomsticks, slapped and punched, restrained with belts and straightjackets, forced to eat until vomiting and confined in a clothes hamper and closets as punishment, the school said.

“The results of this investigation reveal startling and appalling truths. As a school community, we offer a sincere and heartfelt apology to the survivors of the inexcusable actions identified in this report and for the fact that the School did not prevent or stop them,” Executive Director Jeffrey Bravin and Board of Directors President Catherine Burns said in a letter to the school.

School officials declined to comment Friday beyond the report’s findings, The Hartford Courant reported.

The board of directors hired an outside attorney to conduct the investigation after becoming aware of the allegations in 2019, the school said. The attorney interviewed more than 80 alumni, former faculty, staff and other witnesses.

School officials said one former student credibly reported that she was sexually abused by the late Dr. Edmund Boatner, who was executive director of ASD from 1935 to 1970.

“While Dr. Boatner is unable to respond to the allegations, and we recognize his otherwise unprecedented contributions to ASD and the deaf community, we found our alum to be highly credible and corroborated by the constancy of accusation witnesses,” the report said.

The report details other allegations of sexual abuse made against children as young as 10 years old.

The school says all of the allegations have been reported to the appropriate authorities. All of the former faculty and staff named in the report have been banned from campus, and any plaques recognizing them have been removed.