Attorneys representing at least 15 former Northwestern University student athletes announced plans Wednesday to sue the university over allegations that its athletics department fostered a "toxic culture" that facilitated harassment and sexual abuse.

Civil rights attorney Ben Crump said the legal team is also speaking to at least 50 other former student athletes as they prepare the lawsuit.

"What they shared with us was clearly a pattern and practice of a culture that was predicated on physical intimidation, harassment, discrimination, abuse -- both mentally and sexually -- and it was normalized," Crump said at a news conference in Chicago Wednesday.

The announcement comes about a week after longtime Northwestern head football coach Pat Fitzgerald was fired due to allegations of hazing in the Wildcats football program. An independent investigation commissioned by the university prior to the firing found evidence of ongoing hazing that included "forced participation, nudity and sexualized acts of a degrading nature," university president Michael Schill said in a letter last week.

Though the investigation found no "credible evidence" that Fitzgerald was aware of the alleged hazing, the head coach is ultimately responsible for the team's culture, Schill said. Fitzgerald has denied any knowledge of hazing in the program.

Among the allegations laid out by Crump are that players were held down and subjected to "dry humping," were forced to participate in activities "involving nudity and the touching of one another" and were made to "simulate football activities while in the nude." Crump also said some underage players were given alcohol.

Former Wildcats quarterback and wide receiver Lloyd Yates spoke at the news conference Wednesday and described a "code of silence" around the alleged hazing and abuse, saying it was so entrenched in the football program's culture that even some of the coaches took part.

"Upon arrival to campus, we were thrown into a culture where physical, emotional and sexual abuse was normalized. No teammate I knew liked hazing. We were all victims, no matter what our role was at the time," Yates said. "But the culture was so strong that we felt we had to go with it to survive, to be respected and to earn the trust within the football program."

Yates, who played on the team for the 2015 through 2017 seasons, said he was proud to receive an athletic scholarship to play on the team, but the university ultimately let him down.

"We were physically and emotionally beaten down and some players have contemplated suicide as a result," Yates said. "The abusive culture was especially devastating for many players of color."

Crump said the allegations extend beyond the football program. "From our conversations with young men and women, this goes into other sports programs," he said. "We don't believe it's just at Northwestern. We believe it's at many colleges and universities across America, and it must stop now."

When reached for comment Wednesday, Northwestern spokesperson Jon Yates said the university does not comment on pending litigation, but pointed to a message the president released Tuesday -- before the new allegations were made public -- in which Schill said the university will hire an outside firm to evaluate the sufficiency of the athletic department's accountability mechanisms and ability to "detect threats to the welfare of student-athletes."

CNN has also reached out to Northwestern's Department of Athletics and Recreation for comment.

Attorney Steven Levin said Wednesday that the legal team is still interviewing athletes and has yet to file the suit.

"Every day we find out more details, more horrific tales, more things that are going to be part of a lawsuit and we don't feel that it would serve any purpose at this time to rush to filing the case," Levin said.

Investigation found evidence of hazing on football team, president says

Three days before Fitzgerald was fired, Northwestern released an executive summary of the findings of an independent investigation into hazing allegations within the university's football program.

"While the investigation did not uncover evidence pointing to specific misconduct by any individual football player or coach, participation in or knowledge of the hazing activities was widespread across football players," the summary stated.

The investigation did not discover direct evidence that Fitzgerald or other coaching staff had been aware of the conduct, Schill later wrote. It did, however, find there were "significant opportunities to discover and report the hazing conduct."

Fitzgerald, who was head coach for 17 seasons, said in a statement following his firing that he was "disappointed" to learn of the hazing allegations.

Reached for comment on the new allegations raised Wednesday, Fitzgerald's attorney, Dan K. Webb, pointed to the findings of the investigation.

"As far as we can determine, neither the filed complaint nor the press conference presentations set forth any facts or evidence to support any legal claims against Coach Fitzgerald," Webb said in a statement. "As we have stated previously, we will aggressively defend against these and any other allegations with facts and evidence. Further, we intend to move to dismiss the civil suits filed against Coach Fitzgerald and, as appropriate, for sanctions for frivolous filings."

Fitzgerald and the university were named in a separate civil lawsuit filed Tuesday by an unnamed plaintiff who says they were a member of the football team from 2018 to 2022.

The suit alleges Fitzgerald "enabled a culture of racism and/or other microaggressions on the Northwestern football team," and that the football program "has had longstanding issues involving hazing and bullying that takes on a sexual and/or racist tone."

A representative for Fitzgerald told CNN they had no comment on the allegations spelled out in the suit.