OF ALL THE SINS of omission committed by Penn State University in its alleged mishandling of sexual assaults, perhaps the most unforgivable was the failure to find the young boy who was seen being victimized in 2002. It seemed not to occur to anyone to try to identify this child or to consider that he might need treatment and protection. Apparently, shielding the university and its treasured football program came first, and so the boy’s alleged attacker was told simply to keep his activities off-campus.

The abdication of legal and moral obligations at an institution that is supposed to develop young people is inexcusable. Penn State’s trustees appropriately are launching a review into why no one — from the university’s janitors to its legendary coach to its president — didn’t do more to stop what appears to be the serial victimization of boys. Those at fault must be held accountable. The National Collegiate Athletic Association, which held out Penn State as a shining example, needs to confront the shortcomings that make a mockery of its mission to protect student-athletes.

“Nothing happened. Nothing stopped” is how State Police Commissioner Frank Noonan characterized the handling of allegations of sexual abuse by Jerry Sandusky, the football team’s former defensive coordinator. A grand jury has indicted Mr. Sandusky on 40 counts, 21 of them felonies, involving the sexual abuse of eight boys, whom he met through his youth-services organization over a 15-year period starting in 1994. Also charged were Athletic Director Tim Curley and Senior Vice President for Business and Finance Gary Schultz, who the grand jury alleges failed to properly notify authorities and then lied in an attempted coverup. The three men each deny the charges, and there must be a presumption of innocence as the case proceeds.

But if the detailed claims of the grand jury presentment are true, there is no denying the university’s complicity in awful crimes against boys made vulnerable by their ages, their families’ financial circumstances and the promises of help from an adult who held himself out as a mentor. Consider the victims who would have been spared if the university had taken firmer action in 1998 when, according to the grand jury, Mr. Sandusky admitted to inappropriate behavior after complaints from the mother of an 11-year-old. Two years later, janitors witnessed a sexual act being performed in the football facility’s showers but, apparently worried about their jobs, they took no action.

Most egregious was the 2002 incident in which a 28-year-old graduate assistant returning to the football facility was surprised to see the lights and shower on at 9:30 p.m. According to the grand jury, “he saw a naked boy . . . whose age he estimated to be ten years old, with his hands up against the wall, being subjected to anal intercourse by a naked Sandusky.” This would have been a good time to dial 911, but at no point were police or child welfare authorities notified. The graduate assistant told head football coach Joe Paterno, who told Mr. Curley, who brought in Mr. Schultz with the result that Mr. Sandusky was instructed — big deal — not to bring youth to the campus. Mr. Sandusky, his emeritus status at Penn State unchanged, continued his youth volunteer work, and in 2007, according to the grand jury, he victimized another boy.

Because he is an icon of college football, much attention has been focused on Mr. Paterno. What exactly was he told by the graduate assistant? Even though he fulfilled his legal obligation in passing along the complaint, shouldn’t he have followed up? These questions may well end Mr. Paterno’s coaching tenure; there are reports that the trustees are planning his exit. It would be a sad end to an illustrious career but not nearly as sad as the damage done to innocent boys.