A man made it onto a flight at O'Hare International Airport with a gun Tuesday afternoon, according to sources from the Chicago Police Department and the Transportation Security Administration.

There were numerous questions Tuesday night about how such a major security breach could have happened.

Video from fliers showed O'Hare employees making a path down the middle of Terminal 1 as officers ran through. They were searching for a man headed to his gate with a gun.

The Transportation Security Administration said at 12:20 p.m., one of its officers detected an image of a firearm inside a bag going through a Security Checkpoint 2 at Terminal 1 at O'Hare.

TSA policy is for its officers to keep the bag inside the X-ray tunnel and contact Chicago Police.

But before Chicago Police could confiscate the gun, the passenger reached inside the X-ray machine at the checkpoint, took the bag, and left for the gate, the TSA said.

Security screening operations at Terminals 1 and 2 were halted, as the TSA and its law enforcement partners tracked the passenger's movements to a United flight.

One social media user posted, "CPD just yanked a guy off my flight at O'Hare," and added, "Now they made us deplane and do a full security sweep of the plane."

Chicago Police arrested the passenger.

The TSA said its officers found 78 handguns at O'Hare security checkpoints last year — an increase from 2023, when there were 72.

At Midway International Airport, officers confiscated 41 firearms last year — down from a record 50 firearms in 2023.

At O'Hare Tuesday, TSA screening opened again at 1 p.m., about 40 minutes after it was closed.

A police source said tells us the person arrested in this case is a Firearm Owners Identification Card and concealed carry license holder.

Charges were pending late Tuesday.