In June 2012, the New York Times revealed four decades of sexual abuse at the Horace Mann School. Subsequent investigation revealed how a secretive administration turned a blind eye to reports of abuse from the earliest days. Students and parents who came forward were ignored or intimidated. Known serial abusers were kept on for decades or quietly shuffled off to teach elsewhere.

Though the abuse has likely ceased, the silence that abetted it continues. The school has refused to investigate these horrific events. Because of the statute of limitations, no criminal prosecution is possible. In their stead, a group of alumni have taken it upon themselves to organize this independent investigation.

Our goal is not to rehash or accuse, but simply to understand how more than twenty abusers operated for decades with little fear of reprisal. What were the policies and practices that, intentionally or not, shielded and enabled them? Most importantly, what can this tragedy teach us about making other schools safe?

Though what happened at Horace Mann cannot be undone, we hope the lessons gleaned from our investigation and oultined in our report can make schools and students everywhere safer. Here’s how: