BLOUNTVILLE, Tenn. (WJHL) — Twenty years ago, going through airport security was a routine, mostly simple process with limited security screening and processing of passengers. September 11, 2001, forever changed air travel worldwide.

On 9/11, four hijacked planes crashed into the towers of the World Trade Center, the Pentagon and in a field in Pennsylvania. Before then, you did not need an I.D. to fly, anyone could proceed to the gates, liquids were permitted on flights and security screening existed, but not in today’s capacity.

The worst terror attack on American soil led to sweeping travel changes. Since 9/11, officials prioritize safety on a massive scale in hopes of preventing another tragedy.

“It’s almost like the silver lining on a cloud, we are able now to look at our security systems and say, we are as protected as we can be,” said Gene Cossey, director of the Tri-Cities Airport Authority.

Cossey says 9/11 was a wake up call for the aviation industry and exposed the need for system-wide change.

“A lot of people don’t even remember that before that, all bags weren’t screened, they were just thrown on the aircraft,” said Cossey.

In the wake of 9/11, the federal government created the TSA, or Transportation Security Administration, heavily screening all bags and all passengers every day since.

“Their primary goal is to protect people from transportation being used as a weapon,” said Cossey.

Security also saw new bans on many items prohibited from planes including small, sharp objects. Passengers would also have to remove certain clothing items and their shoes when going through security.

Even air traffic control has evolved over the years with new technology to better track and communicate with planes.

“Those are things that are visible, but then there’s also a lot of things underneath the system that you don’t see and we don’t tell people about,” said Cossey.

Passengers remember what it was like to fly before 9/11.

“I miss being able to meet my friends and family as they get off the plane. Having to say goodbye now an hour before they leave, that’s kind of an emotional impact,” said Jean Taylor, a passenger at TRI.

Passenger Joy Maxfield added that flying before 2001 felt much less safe.

“The security has beefed up and we are more cautious with who is coming in and who’s got what,” said Maxfield.

For airport officials, a longer, more painstaking process for security on every level is worth it in light of 9/11.

“Every time you feel inconvenienced by the process that has to happen, that is just one of the steps we are doing to protect you as you travel,” said Cossey.

The terror attacks on 9/11 took the lives of nearly 3,000 people. Saturday will mark 20 years since the attacks.