Frontier flight deplaned after gun magazine found on aircraft

Travelers aboard a Frontier Airlines flight over the weekend in Denver were forced to deplane after someone found a gun magazine on the aircraft, the airline confirmed.

Flight 4765 was scheduled to fly from Denver to Phoenix on Sunday, May 10, when someone aboard found an ammunition magazine on the plane, Frontier said in a statement to USA TODAY this week.

"As a matter of precaution, passengers were deplaned and rescreened," the company said, adding that officials conducted a security sweep but found nothing else.

Customers were booked on a new flight that left the morning of May 11.

According to Frontier Airlines, the magazine belongs to a law enforcement officer. When USA TODAY contacted the Denver Police Department on May 12, the agency said the FBI is looking into the case.

The FBI Denver Field Office told USA TODAY in an emailed statement that its agents are trying to determine whether there was a criminal violation of federal law. The investigation is ongoing, the office added.

The field office or airline did not answer questions about who found the magazine or identify the officer who owns it.

When contacted on May 12, the Denver International Airport referred USA TODAY to Frontier Airlines and the FBI's Denver Field Office for comment.

Other incidents at Denver International Airport

Although there are no links between them, there have been multiple security and safety incidents at the Denver International Airport in the past 14 months, reported the Fort Collins Coloradoan, part of the USA TODAY Network.

Though unrelated, incidents at the Denver International Airport include:

• March 14, 2025 – An American Airlines Boeing 737-800 flying from Colorado Springs to Dallas made an emergency landing, and its engine caught on fire. All passengers were evacuated, and 12 people were taken to local hospitals for minor injuries.
• Aug. 31, 2025 – An Air Canada Airbus A220 set to fly to Toronto returned to Denver and deployed its emergency slides because crew members thought there was a possible electrical fire.
• March 6, 2026 – A United Airlines Boeing 737-800 struck a de-icing truck, subsequently sending an airport employee to the hospital and forcing the airline to evacuate passengers.
• April 19, 2026 – A United Airlines Airbus A321 headed to Washington, DC, was evacuated before takeoff after a reported bomb threat. The plane was screened, and no one was hurt.

Contributing: Trevor Hughes, USA TODAY; Nate Trela, Fort Collins Coloradoan

Saleen Martin is a reporter on USA TODAY’s trending team. She is from Norfolk, Virginia – the 757. Email her at[email protected].