Troubled kids were allegedly strip searched, locked in closets and forced to dig their own graves at a heinous upstate New York boarding school — where local authorities were accused of ignoring the abuse because of the institution’s wealthy owners. A survivor of the hellish Family Foundation School claimed in court papers he was repeatedly sexually abused and described stunning mistreatment at the now-defunct, $80,000-a-year facility in the tiny upstate village of Hancock, about an hour east