BOSTON >> Phillips Exeter Academy, an elite New Hampshire boarding school whose prominent graduates include Daniel Webster and Mark Zuckerberg, disclosed last month that it had forced out a popular teacher in 2011 because of sexual misconduct in the 1970s and ’80s.

The school’s delayed announcement — officials said they had been protecting the victims’ privacy — brought forth allegations against other employees. And on Wednesday, Exeter announced that it had fired a second teacher who had admitted to sexual encounters with a student more than two decades ago.

The revelations at Exeter are the latest to rock the insular, privileged world of U.S. prep schools. In the past decade, sex abuse allegations have tarnished a litany of top private schools, including Horace Mann in New York City, Deerfield Academy in western Massachusetts and the Hotchkiss School in Connecticut. Since December, more than 40 alumni of St. George’s School, an elite boarding school in Rhode Island, have reported several cases of molestation and rape, mostly in the 1970s and ’80s.

Sexual misconduct is, of course, not limited to select private schools. Educators say that it occurs with alarming frequency across all types of educational institutions.

But because boarding schools are usually high-profile institutions with powerful alumni, they receive intense public scrutiny when misconduct occurs on their manicured campuses. The rash of recent allegations and bad publicity has started to yield changes, some experts said, with some schools doing more now to try to prevent sexual abuse and be more receptive to students who report it.

A 2004 analysis of the scant research on sex abuse estimated that 9.6 percent of students in public schools experience some form of educator sexual misconduct, ranging from offensive comments to rape, between kindergarten and 12th grade.

There appears to be no comparable data available about boarding schools, said Peter W. Upham, executive director of the Association of Boarding Schools, who calls sexual abuse by educators “a national scourge.”

Some researchers and lawyers involved with abuse cases say that while very few teachers take sexual advantage of students, some aspects of boarding school life can be conducive to abuse.

“Boarding schools are fertile ground for predatory behavior, mostly because you’re with the kids all the time,” said Eric MacLeish, a lawyer representing several alumni who say they were sexually abused at St. George’s.

“It is accepted that teachers will get very, very close to students as they become mentors,” he said. “They work out together, eat together, take trips together, go to Europe together with the school choir. Many live on campus and are dorm parents.”

Hawk Cramer, 48, an elementary school principal in Seattle who said he was molested by a faculty member at St. George’s when he was a student there in the early 1980s, agreed that the unfettered access to students at boarding schools can allow a pedophile to groom victims.

“You can call kids into your home, you can be alone with them, and kids think you have control over their future,” he said.

And students are loath to report the abuse, at least in real time. “Students are embarrassed and under huge pressure to perform,” Cramer said. “They don’t want anyone to think they aren’t measuring up or that they’re a victim.”

Dr. Eli Newberger, a Boston pediatrician and specialist in child protection, said these are places “where, for the most part, children were treated extremely well, with very high expectations for career accomplishment.” As such, he said, abuse in such rarefied settings “may take decades to overcome.”

Until recently, he and others said, the schools were reluctant to acknowledge bad behavior, and victims had little confidence that their complaints would be taken seriously.

Now, with so many cases coming to light, educators and analysts said that the schools were making greater efforts to prevent misconduct from occurring, and to be more transparent in their reporting when it did.

“I do think a lot of schools are grappling now in a way they haven’t before with what are the best practices in terms of providing safety and enough prevention, training and education,” said David Finkelhor, director of the Crimes Against Children Research Center at the University of New Hampshire.

He noted that by many measures, reports of current child sexual abuse, at least in public schools, were going down. For example, the Minnesota Student Survey, conducted every three years, said that in 2013, less than 6 percent of ninth-graders reported being touched or forced to touch an adult sexually. This was a new low, down from 13 percent in 1992, the first year of the study.

As for the boarding schools, many are conducting more rigorous background checks when hiring staff and are training employees to recognize grooming behaviors among adults. They are also teaching students to identify when classmates seem under stress and when adults might be crossing a boundary.

A number of schools have developed anonymous tip lines and set aside confidential areas where students can air their concerns.

“Now, we have schools sending out pre-emptive letters, even without any allegations, saying, ‘If you are ever harmed or abused, we’re here for you,’” Upham said.

He and others attributed the changes in part to liability concerns stemming from the explosive Jerry Sandusky sex abuse scandal at Penn State in 2011. Sandusky, a coach who was convicted of abusing 10 boys over 15 years, has cost the university more than $92 million in settlement costs.

The Sandusky revelations appear to have been a motivating factor behind the report of sexual abuse at Exeter. According to police documents obtained by The Associated Press through a records request, an Exeter teacher cited the Sandusky case when she reported in 2011 that Rick Schubart, a popular history teacher, had been sexually involved with a student in the 1970s.

The teacher, who had also been a student at Exeter at that time, said that a classmate had told her she had had sex with Schubart, according to The AP. The classmate confirmed to the school that she had had a relationship with Schubart during her senior year in 1977, when she was 18, but said it was consensual. Schubart was forced to resign, and the school said at the time that he left for personal reasons.

In 2015, a 1982 graduate reported that Schubart had sexually abused her when she was 17. Schubart told police it was consensual, The AP said, but the woman’s lawyer told the school she had to have extensive therapy and was seeking financial compensation.

That second report prompted the school to strip Schubart of his emeritus status last year and bar him from campus. Schubart did not immediately respond to a request for comment.

On March 30, school officials disclosed the situation to students, parents and alumni, saying Schubart had been forced out after admitting to misconduct.

The revelations shook the Exeter community and unleashed additional charges of sexual misconduct, which led to the firing last week of a second teacher, Steve Lewis, who admitted recently to abuse that happened decades ago, the school said. The police said this was the only report they received against a current teacher. Attempts to reach Lewis on Sunday were unsuccessful.

Still, the charges set off an anguished debate, in conversations and online, among the close-knit alumni, many of whom had admired Schubart and were trying to reconcile the revelations with their own positive experiences. A few said they knew of the relationship at the time, and were now wrestling with whether they should have reported it and whether their view that it had appeared to be consensual made any difference.

“We have entered a period of sincere reflection about our school’s history and culture,” Lisa MacFarlane, Exeter’s new principal, who has been on the job less than a year, and Eunice Panetta, president of the board of trustees, wrote in a letter Saturday to the school community.

The letter announced that Exeter had retained a law firm to investigate additional allegations and review school policies. It also said outside experts would review how Exeter had handled the Schubart matter, which occurred during the tenure of the previous principal, Tom Hassan, who stepped down last year.

Hassan, who has been censured by the Association of Boarding Schools, has apologized for what he called his “inadequate” response. He said he was trying to protect student privacy.

It remains to be seen whether the episode will affect his wife, Gov. Maggie Hassan of New Hampshire, a Democrat, who is challenging Sen. Kelly Ayotte. Maggie Hassan, who had received campaign contributions from Schubart, was living on the Exeter campus with her husband when Schubart resigned but has said she did not know why he left.

© 2016 The New York Times Company