It's been 15 years. Fifteen years since our nation was attacked. The World Trade Center came down, along with 2,996 innocent American lives.

September 11, 2001, is a day that we will never forget.

I was 6 years old when our country was attacked. At 6 years old, it's hard to understand why the adults are freaking out and why everybody is being sent home from school. But then, I saw it. My baby blue eyes saw the burning buildings as the camera panned vertically. I remember thinking maybe this is just a movie, until my mother held me and cried. She told me what was happening in the best way for a 6-year-old to understand:

"Bad people hit the buildings, but we are going to be okay."

Fifteen years later, goose bumps still trail our arms, the usual battle with tears commences, and our hearts strain as we watch the tributes on every news channel. And even though 15 years have passed, Americans who were affected by the awful events of that day will always remember. We hug our loved ones a little bit tighter on September 11 of every year.

I asked various people to tell me what they remember about September 11, 2001. Here's what they told me.

"I was in kindergarten and I lived on a military base in Ft. Hood, Texas. I was at school and they announced what had happened. They shut down the school and the whole military base. Nobody was allowed to come in or out. It was scary because my mom wasn't allowed to come and get me and my two sisters. It was even scarier because my dad had to go to work and we didn't know what to do."

- Monica Bradley

"I was in college Spanish class when the first plane hit and my teacher tried to make us describe what was happening in Spanish. I'll never forget writing: "'l avión chocó contra el edificio,' (the plane hit the building)."

- Danica Daniel

"I hadn't known why we were being sent home, so on the bus ride, my friend said her dad was supposed to actually have a meeting at the WTC that day. And I said, 'Oh, bummer; I love the city.' I got the most confused looks from all of them. Then I finally got home and my mom told me why we were let out early. My dad was in DC --- he's a government employee --- and not hearing from him for hours was probably one of the scariest afternoons of my life."

- Alissa Katz

"It was the day my 9th birthday party was supposed to happen. I remember how my living room furniture was arranged around the TV set. I remember my mom standing a few feet from the TV with her hands covering her face. She was shaking. I even remember the shirt I was wearing -- a gray Old Navy t-shirt with an American flag graphic on the front. I remember asking why we had to cancel the party. 'We're so far away,' I thought. I just didn't understand what was happening."

- Dillon Havens

"I was working at St John Macomb Hospital. Employees heard the news on patient's televisions. Thought it was a terrorist threat when plane #2 hit. Many employees, patients, families were crying & calling their loved ones. I called my mother first to make sure she was okay. My manager e-mailed everyone to say we could leave because we were nonessential employees. I was in case management. I left about 3 p.m. because I couldn't stop crying. My husband at the time remained at work for 2 days to protect all gas facilities. My sister, Michele, was unreachable and remained underground due to working at TACOM. [My son] was glued to his TV thinking he was going to get called up. I had to keep him away from the TV because it was consuming him. I will never forget that day!"

- Denise Geromette

"I am a training coordinator at TACOM (Tank-automotive Armaments Command) in Michigan. When 9/11 happened, I was in a conference call discussing training programs with others from TACOM around the country. 8 or 10 people were in the call. Then someone came in the room and said, 'Just so you all know, one of the twin towers was hit. It looks like a bad accident.' I thought it was bizarre. Twenty minutes later and they told us the second tower was hit. They turned on CNN and both twin towers were billowing. They put us in lock down for hours before we were evacuated. I was asked to help with TOC (TACOM Operations Center) so I still came into work although we were shut down. Light armored vehicles were in place, army men with guns in hand. I reported to an underground office the next morning, a shell of a room. I was responsible for setting up desks, phone lines, conference calls, and manage headquarters to help send info from us to the army. No calls out or in. I couldn't discuss my job. My family was like, 'Where did Michele go?' The commanding general came down each day for a conference meeting, CNN still blaring. My life was turned upside down. I was in that office 12 hours a day 7 days a week for 3 or 4 months. The emotions were so high, it was so united. What little part I was able to do; I did."

- Michele Hollingsworth

This last story comes from Keith Gay, who was inside of the Pentagon at the time it was attacked.

These are his words:

First of all, my heart goes out to all who lost loved ones and friends, to those who were injured and those who love them, and to everyone who was negatively impacted in any way by the senseless, vicious attacks. The day started off like so many others that time of year. It was another beautiful, late-summer day with plenty of sunshine and blue skies.

Back then I was an active duty Air Force lieutenant colonel assigned to Headquarters U.S. Air Force, so I worked in the Pentagon. Around 9:30 that morning, I kicked off a meeting with a team of people who were doing some work for us. Several minutes later, there was a VERY loud bang. It caused the building to shake pretty hard and rumble for several seconds before gradually fading away. Everyone sat silent for a few seconds, stunned. Someone started to resume the conversation.

I said, “No. Something's different. Something's wrong.” I quickly got up and went into the hall to see if I could determine what had happened. I immediately smelled jet fuel and smoke, and just as immediately heard the building alarm come on.

I ran back into the office and yelled, “We’re evacuating the building. Everyone get out. NOW.”

As people started leaving, I hit the speed dial button on my desktop phone. When my wife answered, I quickly said, “Something happened -- I don’t know what -- and we’re evacuating the building. Don’t worry about me.”

My wife, having seen all the news on TV -- and not knowing what had happened at the Pentagon (just like me) -- very excitedly and urgently asked, “Did you hear about the World Trade Center?!”

Not knowing what had happened in Manhattan, I just couldn’t wrap my head around why she wanted to talk about some building in New York when I was trying to get away from a big explosion. About that time a young captain, a former cadet of mine from the Air Force Academy who had recently left our office to work in another one, stopped by our office to check on us.

He said firmly, “Sir, we’ve got to get out NOW.” I said a quick goodbye and left the office. (Only days later, I learned his office was within about 200 feet from the place the jet hit the building. One moment he was sitting at his desk. The next moment he was sitting about 2 feet away from it, because he stayed in place when the explosion shoved his part of the building a couple feet. He said looking up at the smoke running down the hallway along the ceiling was like looking down at a fast moving stream.)

I knew I could get out of the building quickly by going to the nearest corridor, taking a right, and following the corridor to the stairwell at the other end. As I rounded the corner I saw… hundreds of people walking briskly toward me, because there was already a traffic jam at the stairwell they and I intended to use. (Glancing out a window, I also saw ashes fluttering down from above.)

I called out for people to follow me to a back way I knew, another stairwell. (In hindsight, I bet that’s exactly where they were already headed.) Things slowed down in the stairwell because of all the people trying to get out. Step. Wait. Step. Wait. It was the same way when we got down to the level that led to an exit.

I couldn’t stop thinking, “How did they get a bomb that big into the building?”

I also worried about a stampede and people getting trampled to death. The air was thick with tension, but everyone just kept walking slowly and orderly. (Why so orderly, without panic? In the coming days, it hit me. We had to evacuate the building about 2 weeks earlier. At the time, no one knew why we were evacuating. We just walked out of the building like it was a fire drill. We later learned there was a fire in food service area -- apparently a relatively small, short-lived one. No one I knew saw or smelled smoke. I believe that calm evacuation helped save some lives on 9/11.)

Many thousands of us made it out of the Pentagon safely that day. Very sadly, we lost way too many people in the Pentagon, in Pennsylvania, and in New York."

- Lt. Col. Keith Gay, Ret.

It is hard to forget a day that had such a powerful impact on our country. Not only did innocent people die, but heroes emerged from the darkness to shine light on that dreadful day. Numerous firefighters, police officers, military men and bystanders risked their lives to save the lives of others.

That is what happens when our country is in trouble. What mattered were the lives of the innocent; their families mattered, their friends mattered. Their lives were worth it. No one deserved to die that day.

Our country is still recovering. We're not all better, but we're getting there. For those impacted by this day, I stand with you.

2016 has been a rough year, but we will get through it. Just as we did on September 11, 2001.

For those reading this that lost a loved one on that day, stay strong. American citizens were strong that day, and we shall remain this way. I'll be rooting for you.