(NewsNation) — The Chicago Police Department and the FBI are investigating an incident that took place Sunday, following reports of an altercation between an unruly passenger and a flight attendant, Business Insider reported Monday.

“A disruptive customer on a flight from San Francisco to Chicago was removed by law enforcement upon landing on Sunday, and one member of the flight attendant crew was taken to a hospital for evaluation,” a spokesperson for United Airlines told Business Insider in a statement. “We’re grateful to our crew for handling this difficult situation with professionalism and for putting the safety of our team and our customers first.”

A CDP spokesperson confirmed a total of three occupants of the plane were transported to Resurrection Hospital for observation after the incident, although they did not give official word on their conditions or details of the incident.

In the meantime, video captured and shared on Twitter by passenger Peter Kondelis shows a woman who appears to be screaming on the plane while holding a child.

The footage also reveals several flight attendants attempting to subdue the woman — one even informing her of the plane’s descent.

“Ma’am, we are landing,” someone can be heard saying. “Sarah, step back, fall back, Sarah,” another unidentified voice warns before the video ends.

In another viral video — this time posted by user @Emily_jeannn on TikTok, who was also a passenger on the United Airlines red-eye flight — the woman can be heard saying: “I will kill you. I will f—ing kill you.”

While the public awaits an explanation from the CPD, Emily did offered more information in a follow-up video she posted on TikTok on Sunday.

According to Emily, who filed the incident on TikTok, the woman was yelling “gibberish” earlier in the flight, and had said, “Jesus Christ our savior was going to save us.”

It wasn’t until the flight was descending to land that the woman got out of her seat and refused the flight attendants’ requests for her to sit, Emily explained.

And before Sunday’s tragic encounter, a man boarded a Cincinnati/Northern Kentucky International Airport with a boxcutter last Friday.

The unruly passenger threatened others on the plane, causing the flight to be diverted to Atlanta, where he was arrested.

“A guy in the window seat turned to me and was, like, ‘Hey, he’s got a box knife, he’s been telling me he’s going to stab people,'” one of the passengers told NewsNation’s “Rush Hour” on Monday. “I was scared for everyone,” she continued.

Despite these recent harrowing incidents, on-flight altercations have begun to decrease.

According to FAA’s latest data released Nov. 1, 2022’s rate of unruly incidents (so far) has dropped approximately 80% from the record highs in 2021. 

This is a developing story. Refresh for updates.