A Delta passenger has sued the airline in federal court, alleging an off-duty employee groped and sexually assaulted her on a flight to Minneapolis, and that the attendants over-served alcohol to the employee.

It also alleges on-flight attendants conspired to hide what happened.

The civil suit names Abigail Louise Trebnick-Emerson and Delta Air Lines as the defendants. Trebnick-Emerson was seated on a flight next to Alison Petri, who was in an aisle seat coming home from Las Vegas on Nov. 17, 2022.

Trebnick-Emerson — a Wisconsin resident who also has a Nevada residence listed in a related state criminal case — boarded with a "crew" bag, according to the lawsuit filed Friday in U.S. District Court.

She was using a flight pass that allows her to fly for free or a reduced rate because she works for Delta, the complaint alleges. It does not specify her job.

The complaint says an on-duty attendant served Trebnick-Emerson four cans of wine before she kissed Petri on the mouth without consent.

Petri told the attendant, but he "did nothing" to stop Trebnick-Emerson, the complaint alleges.

The off-duty worker was "obviously intoxicated" and the attendant continued to serve her wine, the complaint says.

After drinking a fifth can of wine, the off-duty worker kissed Petri on the cheek multiple times, despite Petri telling her not to, the lawsuit states. The plaintiff says Trebnick-Emerson vaped on the plane, and that she rubbed Petri's buttocks as she stood to get her bags.

After getting off the plane, Petri told the gate agents about what happened and asked to contact law enforcement.

Trebnick-Emerson, 43, tried to leave the airport after getting off the plane, but she fell down an escalator and airport police responded, the lawsuit states. The court filing also includes security footage, allegedly of Trebnick-Emerson falling on the escalator. She was later charged with disorderly conduct and criminal sexual conduct.

The sexual conduct charge was later dropped. Trebnick-Emerson received one year of probation as part of a "stay of adjudication" in the state case, which means her misdemeanor count of disorderly conduct will be dismissed as long as she completes the probation.

Peter Wold, Trebnick-Emerson's attorney in the state case, declined to comment on the case Tuesday.

The lawsuit accuses two flight attendants of lying about Trebnick-Emerson's behavior on the plane to protect her.

One of the Facebook Messenger screenshots included in the lawsuit shows an attendant telling Trebnick-Emerson that Delta investigators tried to get a statement from the employees who witnessed her behavior, but that they "denied knowing anything and left."

The lawsuit alleges the on-duty attendants provided "false and inaccurate" information about the events.

Trebnick-Emerson said in a message to one of the attendants that she did not remember kissing the woman, before the attendant later states, "Yeah, you were pretty bombed," screenshots in the lawsuit show.

One month after the incident, Trebnick-Emerson sent the other attendant a Facebook message, saying that Petri "filed charges against me based on false accusations and lie(s)," another screenshot filed in the lawsuit attachment shows.

Petri's attorney, Jeff Storms, said in an interview that he is worried about past instances of Delta overserving alcohol to passengers, and in the lawsuit listed four cases of alleged sexual assault by intoxicated people on Delta flights in recent years.

He also raised concern about whether there are deeper issues in the company with attendants protecting other employees after bad behavior.

"To conspire to conceal information from both Delta and law enforcement investigators is deeply troubling," Storms said.

Delta declined to comment on the specific incident in an emailed statement to the Star Tribune. The statement noted that Delta "does not tolerate inappropriate or unlawful behavior," and that "nothing is more important than the safety of our customers and our people."