SAN JOSE, CA — An elite South Bay all-girls Catholic school has issued a public apology after an independent investigation it launched last year revealed a pattern of sexual abuse that goes back decades, NBC Bay Area reports.

San Jose's Presentation High School initiated the probe in September of last year after former Presentation student Kathryn Leehane wrote an op-ed in the Washington Post alleging sexual abuse at her former school.

Presentation issued a public apology that appears on its website's homepage acknowledging the "hurt" sexual abuse survivors experience, and that "the stark truth is that our school did not live up to its commitment to protect you."

The probe, conducted by Van Dermyden Maddux, a Sacramento law firm, revealed a pattern of sexual abuse spanning four decades, from the early 1980s through 2013, the report said.

The investigation didn't include the 2004 allegation of a former student because the case involved pending litigation, the report said.

The teacher involved in the 2004 case has since been required to register as a sex offender after police found child pornography on his computer when he was at another school, the report said.

The results of the Van Dermyden Maddux investigation are detailed in a 37-page report.

"We know that the findings are difficult to read and to digest, however, this investigation was necessary to examine our past to build and maintain a safe and thriving environment for all students past, present, and future, and to ensure we do not repeat any mistakes," the school's statement read.

"To the survivors of abuse, we deeply and sincerely apologize. The stark truth is that our school did not live up to its commitment to protect you. We added further harm when we responded defensively when reports of past abuse began to surface in 2017. We understand that words cannot measure our regret or erase the harm that you endured.

"You were hurt, and we can only hope to make amends by caring for you now and doing everything within our power to ensure that students now and in the future will be cared for and safe."