Colossal TSA failure allowed firearm onboard plane departing Atlanta. Is the shutdown to blame?

A passenger managed to smuggle a firearm aboard a plane leaving Atlanta's Hartsfield-Jackson International Airport on Jan. 3, the Transportation Security Administration announced over the weekend, leading many to wonder if the government shutdown is to blame for the security breech.

TSA agents, who police security checkpoints at every passenger airport in the U.S., are required to work during the shutdown but are not being paid for their work. The predicament has led to an increasing number of agents missing work over the last three weeks.

What are the details?

"TSA has determined standard procedures were not followed and a passenger did in fact pass through a standard screening TSA checkpoint with a firearm at Hartsfield-Jackson Atlanta International Airport on the morning of January 3," the TSA said in a statement, according to CNN.

Delta Air Lines said the passenger boarded a flight headed for Narita International Airport in Tokyo. Sometime during the flight, the passenger disclosed he was carrying the firearm, and the airline immediately informed the TSA. The passenger was cooperative and "was met by Japanese authorities upon landing," the Washington Post reported.

TSA said agency officials have "held those responsible [for the security breach] appropriately accountable."

Is the shutdown to blame?

TSA dismissed the suggestion the government shutdown, which is now the longest in U.S. history, is to blame for the security lapse.

"The perception that this might have occurred as a result of the partial government shutdown would be false," TSA said. "The national unscheduled absence rate of TSA staff on Thursday, January 3, 2019, was 4.8% compared to 6.3% last year, Thursday, January 4, 2018. So in fact, the national call out rate was higher a year ago than this year on that date."

TSA did not, however, provide statistics specific to Hartsfield-Jackson Airport — the busiest airport in the world — or for the security checkpoint responsible for the security failure.

Meanwhile, TSA Assistant Administrator Michael Bilello said on Twitter Sunday that "security standards remain uncompromised at our nation's airports."