CHICAGO — Federal investigators are looking into an alleged assault that happened onboard a United Airlines plane Sunday.

A flight attendant and two others were taken to AMITA Health Resurrection Medical Center for treatment following the alleged incident that was caught on cell phone video.

Flight Attendant and Transport Workers Union Vice President Corliss King said the situation is “said but predictable” and is emblematic of a serious problem.

“This is about noncompliance and unruly, violent behavior on an aircraft, which is a public hazard,” King said.

It is currently unclear whether or not the person taken into custody by police will be charged, but interference with a flight crew member is classified as a felony, punishable by fines or up to 20 years in prison.