A security risk on Saturday morning at the San Francisco International Airport led to the closure of some boarding areas and grounding of flights, according to an airport spokesman.
The shutdown came when a loaded magazine was picked up by a passenger through a security checkpoint around 6:35, said airport manager Chris Morgan.
The result was that the boarding areas at security checkpoints F1 and F3 in Terminal 3 and checkpoint G in the international terminal were closed for about an hour until law enforcement agents were able to locate and interview the passenger.
Aircraft that were not already on the runway also grounded while the search was being conducted, Morgan said. The affected aircraft mainly involved United Airlines.
Transport security management agents flagged the suspicious subject in the passenger's bag at the security checkpoint, but failed to give the given bag for inspection so that the passenger could enter the terminal with the loaded magazine Morgan said.
"The passenger was located, interviewed by law enforcement, cited and allowed to continue traveling. The aircraft resumed normal operation after a 38-minute hill cease," TSA said in a statement.
The airport was packed with people standing in lines. Many of them traveled to the city for the San Francisco game developer conference and waited for security checks to reopen.
"The pre-check line at SFO is no joke 5,000 people long," Andrew Forbes wrote on Twitter.
Airport operations returned to normal around 9am, Morgan said.
Although ammunition can be transported in checked baggage, it is not allowed to use the luggage, according to TSA. It was not immediately clear where officers were in the magazine.
Those traveling with firearms and ammunition clips must secure them in a box or in a hard case.
"Unfortunately, all these security systems put each airport in place, the weakest link is the human factor," says Aviation Analyst Mike McCarron.
TSA said SFO agents are private security personnel and the agency said it will work with the contractor to investigate what happened and how.
Officials said the passenger was quoted by the San Francisco police.TSA may impose a civilian penalty of up to $ 13,333 per breach.