NORFOLK, Va. (WAVY) — Most people can tell you where they were when the events of 9/11 occurred, but Chief Petty Officer Jerome Mapp can tell you what it sounded like — because he was there.

On Sept. 11, 2001, Mapp was working out of the Pentagon’s public affairs office when the first tower in New York City was hit. Without orders to leave the Pentagon quite yet, he decided to step away from the televisions in his office for a moment.

On his way back, he ran into an officer he worked with at Naval Station Norfolk. The officer motioned Mapp to give him a call as he walked by.

He never got the chance to.

Mapp tells 10 On Your Side he later saw the man’s name on a list of casualties from that day.

When he returned to the office, he and his fellow servicemembers received word from the Navy Command Center at the Pentagon letting them know the World Trade Center attacks were believed to be acts of terrorism.

Mapp would learn that first hand only minutes later.

Looking out of his office window, he saw an explosion from the part of the Pentagon adjacent to his. The impact blew out windows and scattered debris, he says everyone took cover.

As people evacuated, Mapp recalls one petty officer second class trying to close a classified safe that’d been blown open.

“Leave it, just go!” Mapp recalled an admiral saying. He added that the admiral waited until everyone else had left before making his own exit.

After getting out of the building, many stayed behind to help others through the jet-fuel-infused smoke. “There was a brigadier general who said ‘If you can’t stomach this feel free to leave. No one’s gonna think bad of you.’ But nobody left,” said Mapp.

The group spent the next several hours helping get others to safety. With his own experience in traumatic situations, he says he was able to keep working, but couldn’t get over this happening on the homefront.

“I’d been in traumatic situations before but overseas… not here. This was something totally different,” he said.

“There was one gentleman who’d got caught,” said Mapp. “There was an open end of the Pentagon, smoke was swirling. He didn’t know where he was even though he was right at the entrance. We kept telling him ‘Put your hands out’ because if we went in, we were gonna become casualties. He stuck his hands through the smoke and we just pulled him and we all kinda landed on each other on the ground.”

It took several hours before Mapp says he started to register what had happened.

“Probably around 1 o’clock in the afternoon, I just kinda looked around the central courtyard and you see people on stretchers, you see people getting bandaged, you see the fires. It was almost like Dante’s hell. It was a very surreal scene. Your mind had to grasp it and get control of it, so you could get control of yourself,” he said.

Throughout the entirety of the day, Mapp continuously saw military chaplains working to comfort everyone.

“I could get over how many there were. Turns out, military chaplains were having a conference at the Pentagon that started that Monday. So there were about 550 military chaplains from the command worldwide on 9/11… God knows what he’s doing,” said Mapp.

Today, less than 24 hours before the 20th anniversary of the attacks, Mapp tells a story of survival. He’s hoping it makes others reflect on those who weren’t as fortunate that day.

“I want people to think of the moms, dads, children who didn’t come home that day… I feel like I need to carry on. Obviously, in any tragedy, there’s gonna be survivors. You just gotta forge ahead you remember the tragedy. You pray for those who died, you pray for their families, but ultimately you have to move forward. You can’t stay in one place,” he said.