New Brunswick, N.J. - Rutgers' coaching scandal spiraled deeper Friday, bringing down the popular athletic director and a school vice president while donors threatened to cut off their contributions to New Jersey's largest public university.

The day of mounting troubles for the school began with athletic director Tim Pernetti resigning over his failure to immediately fire coach Mike Rice, who was caught on video hitting, kicking and taunting players with anti-gay slurs at practice.

The video was shown Tuesday on ESPN, prompting outrage nationwide and on campus, where the coach's conduct was especially sensitive because of the 2010 suicide of a student who killed himself after his roommate used a webcam to record him kissing another man.

Rice was fired by Pernetti on Wednesday, but the athletic director immediately came under criticism for only suspending and fining the coach after the video was brought to his attention four months ago. Pernetti said Friday he wanted to fire Rice on the spot but did not because the consensus among school officials at the time was that it didn't warrant dismissal.

Rutgers president Robert Barchi came under harsh questioning from reporters at a news conference Friday over what he knew about the video months ago, but he got a nod of support from New Jersey Gov. Chris Christie and the school's board of governors.

Barchi, who took office in Sept. 2012, said he first saw the video only this week, but was aware it existed in late November when Pernetti gave him a summary of what was on it at the time.

"This was a failure of process. I regret that I did not ask to see this video when Tim first told me of its existence," Barchi said. "I want to apologize to the entire Rutgers community for the negative impact that this situation has had on Rutgers."

Based on the information he received from Pernetti, Barchi said he "agreed with and supported his recommendation to suspend, rather than fire, coach Rice at that time. It was not until Tuesday evening of this week, when I watched the video, that I had the opportunity to witness personally for the first time what Tim had seen last fall.

Barchi said the school hopes to appoint an interim athletic director in a few days but he admitted he had no idea whether that person would come from inside or outside the university.

The 42-year-old Pernetti is a Rutgers graduate who played tight end for the Scarlet Knights from 1989-93.

Pernetti said in his resignation letter to Barchi that "my first instincts when I saw the videotape of Coach Rice's behavior was to fire him immediately. However, Rutgers decided to follow a process involving university lawyers, human resources professionals, and outside counsel."

"Following review of the independent investigative report, the consensus was that university policy would not justify dismissal. I have admitted my role in, and regret for, that decision, and wish that I had the opportunity to go back and override it for the sake of everyone involved," it said.

Pernetti enjoys popularity among Rutgers alumni and donors, especially after he helped the school move to the Big Ten, which means millions in additional revenue from TV contracts and more national exposure, especially in football.

Two of Rutgers' leading donors have threatened to cut their contributions in the wake of Pernetti's resignation.

Tom Mendiburu, whose High Point Solutions paid $6 million for the naming rights to the football stadium, said he was concerned because he made the deal because of Pernetti.

And the Star-Ledger of Newark reported that Daniel Wheeler, a founding member of the Society of Queens College, where membership requires a minimum of $1 million donated over a lifetime, was upset Rutgers ignored prominent donors' pleas to keep Pernetti.

Also resigning was John B. Wolf, Rutgers' interim senior vice president and general counsel, who is believed to have recommended against firing Rice in December.