An unnamed teenager who alleged she was sexually assaulted at a University of Chicago frat house has filed a lawsuit, alleging the fraternity did not do enough to prevent sexual assaults, despite several other reports dating back to 2009.

The teen has accused Alpha Delta Phi and its University of Chicago chapter of multiple counts of negligence, alleging "both ignored known sexual assault risks at the house and failed to put meaningful safeguards in place," attorneys for Jane Doe said in a statement Tuesday.

The teenager says she was unable to provide consent when she was sexually assaulted on Feb. 7, according to the lawsuit.

After the alleged sexual assault by a then-member of the frat, Jane Doe was found "struggling to speak and required assistance to walk" as she left the room, according to the suit.

The fraternity told ABC News it "suspended the member involved" after "learning of these allegations." ABC News has reached out to the University of Chicago for comment.

The fraternity member accused of sexual assault did not immediately respond to ABC News' request for comment.

The lawsuit comes days after another allegation of sexual assault was reported at another fraternity near the University of Chicago's campus.

History of incidents

The lawsuit alleged that Alpha National "undertook the responsibility of educating its members … on the prevention of sexual violence and preventing sexual violence among its members."

The lawsuit says there were two reports of alleged sexual assault in 2009 at Alpha Delta Phi Chicago’s fraternity house five days apart. In 2022, an anonymous social media post also alleged a sexual assault at the same fraternity house, according to the suit.

The lawsuit alleged that between 2009 and Feb. 7, 2026 — when Jane Doe was allegedly assaulted —Alpha National "received additional reports of sexual misconduct involving Alpha Chicago members or Alpha Chicago social events."

Despite these reports, "Alpha National did not impose an interim suspension on Defendant Alpha Chicago, did not restrict or condition Alpha Chicago’s social events, did not require that the residential floors of 5747 South University Avenue be secured during events, and did not require that sober monitors be stationed at access points to the residential floors," according to the lawsuit.

The suit alleged the fraternity made public commitments to sexual assault prevention; still, it failed to enforce its own policies at chapter events, attorneys for Jane Doe said in a statement.

The alleged assault

Jane Doe attended a party at the frat residence on the day of her alleged assault, according to the lawsuit.

A member of the fraternity offered Jane Doe a shot of "unidentified alcohol" and encouraged her to drink it, according to the lawsuit. Almost immediately after, Jane Doe began to feel unsteady and lightheaded, according to the lawsuit.

The frat member then directed her to follow him to a secluded room in the fraternity house, taking her up the stairs to a bedroom on the residential floor, according to the lawsuit.

Jane Doe allegedly told the frat member she was feeling "unsteady and lightheaded," which the suit alleges he "purposely ignored" before directing her to move toward the bed in the room, the suit says.

Jane Doe then "lost all physical and verbal ability to refuse" her attacker, according to the suit.

The alleged attacker then began to make "unwanted and nonconsensual sexual advances upon Jane Doe," the suit alleged.

The suit alleged that at this point, Jane Doe was "mentally and physically" unable to provide consent.

Following the alleged assault, the frat member "left Jane Doe alone and unconscious in the room where he assaulted her limp body in the fraternity house," according to the suit.

Jane Doe’s friend then learned that Jane Doe was "upstairs, unconscious in a bedroom," the suit alleged. Jane Doe’s friend found her unconscious and, as she left the room, struggling to speak and needing assistance to walk, according to the suit.

Jane Doe awoke the next morning to find blood stains in her underwear and she reported the assault to the Chicago Police Department, according to the lawsuit. The suit alleges the Chicago police investigation is ongoing.

Alpha Delta Phi National told ABC News it is aware of the allegations and is taking them "extremely seriously."

"The conduct described is deeply troubling and inconsistent with our values. We are committed to the safety and well-being of our members and communities and will cooperate with law enforcement as appropriate. Because this matter involves an active lawsuit we cannot provide further information on the specific circumstances at this time," the fraternity said in a statement.

Jane Doe is seeking damages for physical injuries, emotional distress and ongoing psychological harm, according to her attorneys.

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