EAST LANSING, Mich. – Michigan State's athletic director retired Friday, two days after the university president resigned over the school's handling of sexual abuse allegations involving former doctor Larry Nassar and two hours before ESPN released a report detailing allegations of sexual assault and violent attacks on women involving Spartans football and basketball players.

Mark Hollis, who had been athletic director for 10 years, disclosed his decision to retire during a meeting with reporters on campus. He was asked why he would not stay on.

"Because I care," Hollis said, holding back tears. "When you look at the scope of everything, that's the reason I made a choice to retire now. And I hope that has a little bit, a little bit, of helping that healing process."

Hours later, the university named its vice president to serve as acting president after the departure of President Lou Anna Simon. Bill Beekman is expected to serve briefly in the role until the board of trustees can hire an interim president and then a permanent leader.

Also Friday, USA Gymnastics confirmed that its entire board of directors would resign as requested by the U.S. Olympic Committee (USOC). The USOC had threatened to decertify the organization, which besides picking U.S. national teams is the umbrella organization for hundreds of clubs across the country.

Some of the nation's top gymnasts, including Olympians Aly Raisman, McKayla Maroney, Simone Biles and Jordyn Wieber, said they were among Nassar's victims.

At the university board's meeting, Chairman Brian Breslin said it was "clear that MSU has not been focused enough on the victims." The trustees, he said, want to resume discussions with those who have sued the school to "reach a fair and just conclusion." Talks broke down last year.

The board plans to ask an independent third party to review health and safety at the school, and it wants state Attorney General Bill Schuette to consider appointing a neutral investigator to conduct an inquiry of the Nassar matter.

Trustee Brian Mosallam addressed his remarks toward the victims: "I am so truly sorry. We failed you."

Simon submitted her resignation Wednesday after Nassar, a former Michigan State employee, was sentenced to 40 to 175 years in prison for molesting young girls and women under the guise of medical treatment.

ESPN released an in-depth investigative story about two hours after Hollis' announcement and scrutinized the way football coach Mark Dantonio and basketball coach Tom Izzo handled allegations of sexual assault against their players.

ESPN's report details incidents involving MSU's football program involving 16 players since Dantonio took over in 2007. Four Spartans football players — Josh King, Donnie Corley and Demetric Vance in a January 2017 incident and Auston Robertson in an April 2017 incident — were dismissed last year and are facing criminal sexual conduct charges.

ESPN also detailed alleged sexual assault involving a student assistant basketball coach and two basketball players.

The Associated Press and the Detroit Free Press contributed to this report.