The principal of Denver’s East High School has retired after an investigation into how school district officials handled complaints about the actions of the school’s cheerleading coach found principal Andy Mendelsberg “did not take the necessary steps to ensure that the physical and emotional health and safety of the students on the cheer team was fully protected,” according to a letter from Superintendent Tom Boasberg.

Former East principal John Youngquist will return to Denver to lead the school, Boasberg announced Friday. Youngquist served for the past four years as a top official in Aurora Public Schools.

East is the most-requested high school in Denver Public Schools. The 2,500-student school is known for its comprehensive academic program, as well as its breadth of sports and extracurricular activities.

Mendelsberg had been on leave since August, when 9News first aired videos that showed East cheerleaders being forced into the splits position while teammates held their arms and legs and former coach Ozell Williams pushed them down.

The parents of at least one cheerleader who was injured by the practice emailed a video to the East High athletic director in mid-June asking “what the administration is going to do about my daughter’s injury and how it happened,” according to emails provided to 9News.

After the 9News story broke two months later, Williams was fired.

Mendelsberg’s exit coincides with the conclusion of an independent investigation by an outside law firm commissioned by DPS. The district on Friday released a report detailing the firm’s findings.

According to Boasberg’s letter, the investigation found that “over multiple months, in response to multiple concerns of a serious nature,” Mendelsberg and East athletic director Lisa Porter failed to keep the students on the cheer team safe.

Specifically, the letter says Mendelsberg and Porter did not “sufficiently address, share or report allegations of abuse and the contents of the videos;” failed to provide the necessary level of oversight for the cheer coach, “especially as concerns mounted;” and failed to take corrective action, including firing Williams.

At a press conference Friday afternoon, Boasberg said that in addition to what was captured on video, concerns about Williams included that he instructed athletes not to tell anyone what happened at practice and required them to friend him on social media “with the express purpose of him monitoring their social media presence.”

Boasberg said that “raises deeper concerns about what was going on here.”

Mendelsberg, Porter, assistant cheer coach Mariah Cladis and district deputy general counsel Michael Hickman were put on leave while the investigation was ongoing. The Denver police also launched an investigation.

Porter resigned her position earlier this week, Boasberg said.

Hickman received corrective action but is being reinstated after the investigation revealed he didn’t know the full extent of what happened, Boasberg said.

Cladis, who was not at practice during the splits incident and whose position was volunteer, is welcome to remain the assistant cheer coach, he said.

Mendelsberg had been principal since 2011. But he’d worked at East much longer as a teacher, softball coach, dean of students, athletic director and assistant principal, according to a story in the Spotlight alumni newsletter published in 2012.

Youngquist preceded Mendelsberg, having served as principal of East from 2007 to 2011. He left the school to take a districtwide position leading the recruitment and development of DPS principals. In 2013, Aurora Public Schools Superintendent Rico Munn hired him to be that district’s chief academic officer, a job he’s held until now.

Regarding his decision to return to East, Youngquist said, “My heart has drawn me toward supporting this learning community now and well into the future.”

As a parent and school leader, he said he understands the trust that parents put in schools. “I’m committed to strengthening that bond and partnership with our young people, our parents and with our great East staff,” he said.

Munn has already appointed an interim chief academic officer: Andre Wright, who currently serves as a P-20 learning community director. In a statement Friday, Munn said he “will evaluate the role and expectations of the (chief academic officer) position prior to developing a profile for that position moving forward.”

“We thank John Youngquist for his four years of service … and wish him all the best in his next chapter,” Munn said.

Chalkbeat reporter Yesenia Robles contributed information to this report.