How borders are drawn and enforced has far-reaching consequences, whether we live on either side of them or halfway across the world.

This article is more than 2 years old.

January 7, 2017 This article is more than 2 years old.

“You may transport unloaded firearms in a locked hard-sided container as checked baggage only,” the Transportation Security Administration informs passengers.

This fatal flaw of US airport security was exposed when a gunman opened fire today in a baggage claim area of Fort Lauderdale–Hollywood International Airport in South Florida, killing at least five people and wounding at least eight, according to local officials.

The alleged gunman was an arriving passenger and pulled a weapon from a previously checked piece of luggage, a county official said, according to the Associated Press.

Passengers simply have to declare the gun and ammunition when checking their bag. US authorities tell passengers to consult local gun laws.

The TSA confiscates hundreds of guns a year from security checkpoints and uses social media to remind passengers how to better transport other weapons that the US government permits in checked luggage, like knives, cattle prods and throwing stars.

“While firearms are prohibited in carry-on bags, you can pack them in your checked baggage, as long as you meet the packing guidelines,” TSA said in an October post that showed a photo of a gun confiscated at Houston’s William P. Hobby International Airport.

Friday’s attack exposes another security threat at US airports: exposed areas. Known as landside areas, departure halls and baggage claim areas can be easily accessed by pretty much anyone. This occurred last March during the terrorist attack at Brussels Airport.

In addition to fixing aging US airports, perhaps authorities will soon reconsider their security policies.