CONWAY S.C. (WBTW) — Sunday marked 21 years since terrorists hijacked four planes and crashed two of them into the World Trade Center in New York, killing nearly 3,000 people.

Through annual ceremonies, those who died when the planes crashed at the World Trade Center, at the Pentagon, and in Shanksville, Pennsylvania, are remembered and honored on this day.

Roughly 20 American flags stood tall along the Main Street bridge in Conway Sunday morning, held by members of American Legion Post 111.

“We’ll be standing from the time the first plane hit the twin towers til the last plane crashed in Pennsylvania, which is 8:30 to 10:30,” American Legion Post 111 Cmdr. Donald Deane said.

Post 111 officials said the “Flags Over the Bridge” event is to remember all of those who died on Sept. 11, 2001, including first responders.

“It is the worst disaster that we’ve had, and what Post 111 does here in Conway is just a small token to what we can do to remember all the lives lost, civilian and military,” said Jeff Pino, flag coordinator for American Legion Post 111.

Pino said Sunday morning’s clear skies looked eerie.

“We could actually stand on a bridge that went over the New Jersey Turnpike, and we could actually see everything clear as a bell,” Pino said. “Like I had said earlier, when you look at the sky today, it’s very eerie because this is the way the sky looked that tragic morning.”

Conway Fire Rescue was also at the bridge Sunday morning. The ladders from two fire trucks were extended over the bridge in remembrance of 9/11.

“We cannot forget these people,” Deane said. “We cannot forget the fact that we were attacked on our own soil, which is a first and hopefully the last and I for one think it’s extremely important that we do this. We cannot forget that day.”