In honor of the 17th anniversary of 9/11, the General George Patton Museum opened up its 9/11 display to visitors that day only. Prominent in the display is a Fort Myer, Virginia foam truck that was on duty in front of the Pentagon when American Airl...

J. Scott Harper, a lieutenant at Fort Knox Fire and Emergency Service, remembers Sept. 11, 2001 well. He was working at Fire Station #1 the day an airplane crashed into one of the World Trade Center towers.

Like many others who lived through 9/11, Harper remembered where he was when he got the news.

He had just hired on three months prior as a firefighter with the department from a position in Radcliff. It was just a typical morning for the seven-year veteran -- until the typical ended with an announcement.

"Someone said, 'Hey, there's a plane that hit the towers,' so we all ran into dispatch and looked at the TV," said Harper. "We're thinking a Cessna or something small just hit the towers and some firefighters are going to be working hard on a high-rise."

Many firefighters soon lost interest and went back to the business at hand. Shortly after, someone hollered again, this time exclaiming that the situation was getting out-of-hand.

"We came back in and about that time, we saw the second airplane swing around and hit the tower on the other side," said Harper. "That's when everybody was like, 'Aw man, this is not an accident.' There was no way they couldn't have seen the other tower as bad as it was smoking."

One building over from Harper, Pat Walsh was busy planning construction projects. Back then, the director of Fort Knox Directorate of Public Works worked as an engineer for the organization.

Walsh said because the armor center was still in operation then, the post population was large.

"Somebody called me down from our Engineer Services Division; they had a TV on back there," said Walsh. "They were showing a replay of the first plane that hit the tower. The news was live from the area."

Walsh said many also thought that first plane crash was simply a terrible accident, maybe a pilot that had somehow veered off course. As they sat around watching the footage, the unthinkable suddenly happened.

"They actually showed live the second plane hitting the tower," said Walsh. "At that point, you realize that this isn't an accident. Everybody became immediately concerned because we didn't know what was the next target.

"Obviously, we are close to the Gold Vault, which is known worldwide, so there was concern from everybody on what the next target was and what was going to happen next."

Walsh said they all stood by and waited for further guidance from post commanders. Meanwhile, Harper and his fellow firefighters had jumped into action, receiving orders from higher ups to ensure safety around the post and watch for other airplanes, some of which were still unaccounted for at that time.

"I remember seeing the gun trucks going by with the machine guns mounted on them," Harper said. "I remember thinking, 'Man, this is really getting real now' -- and long lines at the gate. That's when you could really tell everything was different."

Walsh remembered the long lines, too. He was considered to be "essential personnel" and, as such, had to go into work the next day. Knowing they only had the Brandenburg Gate open to ensure the highest security, he decided to leave a little earlier from Elizabethtown. At 6:45 a.m., he found himself stuck in traffic on 31W near the Gold Vault.

"I got to work at noon," Walsh said. "Probably the most significant thing I did at work that day was order porta-pots to be set along 31W on government property so if traffic backed up that far the next day, people would have someplace to go."

Harper said the moment the second airplane crashed into the tower and then both towers collapsed seemed completely surreal to him. He had visited Manhattan in September the year before to visit a friend and had walked into the lobby of one of the Trade Center towers.

Sometime after the terrorist attacks, Harper's wife reminded him of a photo his friend had taken during his visit. In the picture, Harper is leaning out from the side of a ferry with the World Trade Center towers in the background.

Walsh said people's attitudes about security changed that day, for the better.

"The post is better off from a security standpoint. It got everybody's attention that maybe we thought we were a little insulated from stuff like that," Walsh said. "We're much more secure now than we were then."