Steve Lewis: The 9/11 terror attacks permanently changed the face of American national security and made counterterrorism a top priority for the FBI.

But their immediate aftermath also brought out the best in many Americans—including thousands of FBI special agents and professional staff employees who selflessly answered the call to investigate and help their nation recover from the single-deadliest day in its history since the attacks on Pearl Harbor on December 7, 1941.

As we mark the 20th anniversary of 9/11, our host Jennifer-Leigh Oprihory brings you the story of one of those first responders: Supervisory Special Agent Tom Duffy.

Two decades later, the day’s impact still weighs heavily on the hearts and minds of many 9/11 first-responders. Duffy sat down with us in hopes of helping others like him feel empowered to share their stories (potentially for the first time) and seek out the support they might need. He’s also sharing his account to help ensure that the weight of that day and the sacrifices made by FBI personnel and other responders aren’t lost in the passage of time.

As part of this episode, we’ll be including detailed descriptions of evidence recovery efforts related to ground zero in New York. Some people might find this material disturbing. Listener discretion is advised.

I’m Steve Lewis, and this is Inside the FBI.

Jennifer-Leigh Oprihory: The morning of September 11, 2001, didn’t start in an especially remarkable way for then-Special Agent Tom Duffy, who’d been working in the FBI’s Philadelphia field office for about four years at that point.

Tom Duffy: My partner and I, we said, "Okay we're going to do this or that today,” and all of a sudden, we hear from one of us going, "Hey, there's been a plane crash."

Oprihory: Soon after, the head of the Philadelphia Evidence Response Team—the field office’s dedicated crew of on-call crime scene first-responders—approached Duffy to see if he wanted to travel to New York City to help backup the National Transportation Safety Board in the wake of the attack.

Duffy: He says, "Hey, if we get called out, would you like to go?"

Oprihory: At this point, I need to pause the recollections and give you some crucial context.

If Duffy’s career was a movie, and you were to fast forward a bit, you’d learn that he eventually went onto lead training for FBI Headquarters' Evidence Response Team Unit. On September 11, 2001, though, he was a 38-year-old U.S. Army veteran who’d never worked on an Evidence Response Team, or ERT, before.

An ERT’s main duties are to secure, document, and collect evidence from crime scenes and then properly package and transfer that evidence to the FBI Laboratory for further analysis. Duffy was interested in learning more about serving on the ERT but hadn’t formally applied.

Duffy: One of my best friends in the squad was in ERT, and another one who sat 10 feet away from me and he was another team leader, so they were recruiting. I had expressed interest, stuff like that, and then 9/11 occurred.

Oprihory: And so, when offered the chance to deploy on a response—a standard way teams gauge whether someone interested might be a good fit—Duffy accepted.

Duffy: And then more reports came in, then the second plane, and they're like, "Uh -oh, this is not an accident" at this point. And then, you know, as history went, and we started figuring out more and more. So, the team lead comes, and he's like, "Do you still want to do ERT?" He's like, "Yeah, 'cause we just got the call that we would be deployed."

It's like, "Count me in. What do I do?"

Oprihory: Duffy then received instructions to head home, pack for a weeklong trip, and then return to the office that afternoon.

And that’s how his experience as a first-responder began.

Duffy: I didn't have a uniform like I'm wearing now, I did have steel-toed boots, though I didn't have a helmet, but, you know, eventually we got some of that stuff. There was five of us, total, that were not really ERT members, but were thinking of joining the team.

Oprihory: Duffy’s team was then placed on standby. As more news reports poured in, the team played the waiting game at an offsite location until they got confirmation that they would deploy the next day.

Duffy: So I had all that night to think about it, because I'd never gone on ERT deploying before. Next day, I don't know what time it was, said goodbye to my family, hop in, and then we convoy up there. And again, it was a beautiful weather day. And myself and the team leader were in the van, and I'm asking questions, "Okay, what do we do? How do we do this? What happens if a plane crash? What happens..." I mean, ‘cause I'm new to this. I mean, I'm an investigator, but I'd never done this before. So he's giving on-the-job training in the couple-hour drive up there, and I'm taking mental notes.

Oprihory: The team’s first stop was Newark, New Jersey, since the local field office there was coordinating the response to the attacks at ground zero.

Duffy: We could see across the river, the smoke coming from ground zero. You can't really see ground zero, but you can see the smoke, and I found it very surreal. There was helicopters and a lot of activities, and people always say the same thing: It seemed like a war zone, and we hadn't even got close to it.

Oprihory: But as the Philadelphia-based team of 23 gathered their gear, they learned that ground zero wasn’t going to be their destination that day. Instead, they were headed to Fresh Kills Landfill in Staten Island—a borough of New York City across the river from Manhattan—where rubble from ground zero was being transported for processing.

Duffy: They were taking stuff from ground zero, putting it in backs of dump trucks, dump trucks would go into docks, transfer to barges, barges come across the river, and then they would put it back on dump trucks. The dump trucks would drive a few miles to us, and then we'd say, "Okay, that dump truck, dump it here. You three guys, go [to] that pile."

And it was just piles of rubble, you know, building material, things like that, that was literally scooped up from ground zero itself. And we were told that, you know, the firefighters, you know, there's still rescues going on, so we didn't know quite what we were gonna find. At that point, more and more information’s coming out as to who did it and what happened.

There was still investigation going on. There was other subjects, perhaps, out there, other planes. I mean, it was chaos.

So, okay, so our job here is to sift through this rubble, find evidentiary stuff about the hijackers who had done it, things like that. So we’d just start setting up debris fields, "Okay, this dump truck goes here." It was spread out, and we just used hand and start moving things out and going through it. "Okay, you know, this is building rubble, this is a plane part." We were kinda sorting it out. You know, "This could be possibly human remains. This is personal effects." We set up bins that we were separating things for later examination, 'cause it was just raw material coming in.

We had no idea, at that point, the amount of rubble and the amount of material, I guess, that was gonna come our way over the next month. We went in there with everything we had, but it wasn't near enough. And we set up a couple of tents. It was big open air, I remember it was very hot that day, and we had a bunch of rakes and shovels we lined up, and then, within a few hours, dump trucks were coming from the river.

By the end of the first day, it was dark, we didn't have lights. We had no bathrooms, no food, so we would send people to McDonald's and stuff like that. Very little security there, except us, and eventually more and more people, the media and more and more people figured out, OK, these dump trucks keep going over there. I mean, we were trying to hide it, but you can't.

Oprihory: He said the team received support from the Army National Guard within a day or so.

Duffy: I can't talk enough about those guys. They said, "What do you need us to do?"

Oprihory: The troops brought the ERT members food, set up portable toilets and security, set up barbed wire around the site, and more.

Duffy: They put up tents for us, we were eating MREs—

Oprihory: —or meals-ready-to-eat—

Duffy: —but myself, my team, they were all army. It was like, this is like being out in the army again.

Oprihory: Duffy said that the enormity of the operation helped the team press on despite the weight of what had occurred across the river.

Duffy: I was like so focused on that, I was kinda blocking off the tragic part of it, because, at this point, I was just trying to do the best job I could, because I was new to the team, and I didn't want to screw anything up.

And we, at that point, had an inkling about the number of victims, families, I mean, that was in the back of our minds was like we knew we couldn't do anything until we had a processing scene set up, so we were struggling with that. And that took us the first couple of 20-hour days, and it was just an enormous task, but we all bonded together. So, "OK, you do this, you do that."

Oprihory: In addition to rubble, the ERT had to process cars that were being dug out of ground zero and surrounding areas and then sent over to Fresh Kills. Since Duffy was the team’s resident car enthusiast, he and another agent set up a car yard, and they tag-teamed going through vehicles.

Duffy: We had to go into the cars and pull out identifying materials, human remains if there was any, plane fragments, whatever we could find, so we treated each car like its own little scene.

Oprihory: However, he noted, they didn’t have the kind of equipment needed and wound up getting backup from firefighters.

Duffy: The volunteer firefighters came up in their turnout coats, and they had jaws of life, and they had saws, because we were getting cars that were intact, just covered in dust, with asbestos, stuff like that, which [was] another thing, a lot of us didn't have proper gear.

Oprihory: According to Duffy, the fact that the Evidence Response Team members lacked personal protective equipment for their work environment took a heavy toll on their morale.

Duffy: We kind of felt abandoned. All of the material was going to ground zero; that was the focus, but we were dealing with a different set of circumstances. We weren't necessarily digging through rubble at the scene, but we were re-digging through it when it was transported.

So, we were going through gloves, we were going through Tyvek, and we're running out of gear and equipment... but they sent firefighters up there with their gear, and it was great.

Oprihory: And even though they were working with rubble and cars, some scenes the ERT and other responders witnessed at Fresh Kills left them emotionally wrecked.

Duffy: The hardest part was some of the cars we were getting out of there, and some of the firetrucks, we were finding remains of firefighters in there and that were crushed and didn't escape, and we had firefighters helping us, so it was kind of surreal.

And the worst part, I think, was when relatives, family members of the firefighters were allowed to come onto the site. And, you know, the firefighter trucks have like “Engine Company this,” you know, “Engine Company that,” and I remember a group of firefighters came in and said, "Yeah, that's our buddy's truck."

They wanted to go in, and they brought a woman and her little boy, and that was his father's truck. That was a little rough for all of us. And so, we let them have a few minutes there, and they had a little ceremony.

But that was the roughest part for me and the guys with us, because that's when it came home to us, the impact. I mean, we knew the impact on us. We knew the impact on the nation. We were paying attention.

Oprihory: However, he recalls, the universe sent him at least one reminder that he wasn’t alone.

Duffy: On day four, I'm working with another firefighter, and they're, you know, they’re great. I was like, "Look, I need that door open." And they'd jump on it, they'd take care of it for me, and they'd help me take stuff out. All of a sudden, a guy comes up behind me and [gives me] this big bear hug. And he picks me up, and I turn around—it's my cousin.

And he was from Clifton, New Jersey, and he’s a firefighter there. I had no idea he was responding. He had no idea I was there. I'm all Tyvek'd up, and he saw and he had, I assume he recognized me, and he snuck up behind me.

He and I, you know, there's a picture of the two of us—we're just covered in dirt and stuff like that—but I hadn't seen him in years, and it was just—it was the last place I thought I was gonna run into him.

Oprihory: Duffy said his teammates made it their duty to protect the people whose remains—either physical or sentimental—they were able to uncover.

Duffy: People tend to live in their cars, and you know, we were finding mementos. I remember one time we popped open the trunk of a car and in it was an anniversary gift, wrapped, you know, a bottle of wine, some cards that, you know, I presume a husband may have bought on the way into work or whatever and was gonna surprise...

We don't know all the stories, we just know what we found, and we didn't have time. We took pictures, we noted. At that point, it was turning to less an investigation, but more, "OK, we're going to match items up to the victims' families." And we set up an assembly line that way, because [as] more and more days went on, we kind of knew what happened, now it was, okay, we turned to victim recovery mode at that point.

We would find human remains and say, "OK, we have to segregate them, get them refrigerated." And then, you know, the [FBI] Lab would, you know, and the mortuary technicians would take care of that, but we would collect it and send it there. But we found little mementos of people's lives that were frozen at that time when the event happened, and it was kind of a time capsule of what, you know, we would just kind of speculate at the end of the day, "Well, we found this. I wonder what that meant. I mean, I wonder what was going through that person's mind."

And that's what brought it home, even though obviously none of the team was there at ground zero, and none of us, obviously, you know, it happened to us, but we were, I guess, living out the events through the articles and the items we were finding.

So that's why we guarded them. You know, I mean, it was almost sacred ground.

We had only a small portion of it, but, you know, seeing the impact on the victims, I think, was the toughest thing for me, and that's what brought it home.

Oprihory: The team found solace in post-work gatherings at their hotel, where they would crowd into their team leader’s room.

Duffy: And we would sit down and have beer and pizza and we would de-stress. We would just talk about what was going on.

A lot of the guys I knew, some I didn't, but we all kind of banded together because of that experience. We kind of became very insular that way, but, you know, we got the job done every day.

Oprihory: What started as a weeklong assignment lasted nearly to September’s end.

Duffy: We rotated out of there, I believe, September 30th. It was near the end of the month, and another team took our place and continued to build, and one of our team leaders volunteered to stay there as continuity, and he was there 'til next May, I believe.

And then we had unfinished business.

Oprihory: Duffy and his colleagues returned to Fresh Kills to assist with ongoing recovery efforts in January 2002, and then again that May once the site was shut down.

Duffy: It was just enormous, the amount of work and effort that had to go in at, well, all the sites. Shanksville, Pentagon, where we were, obviously ground zero. We were there for about, I think, two or three weeks.

Oprihory: While there, a member of the FBI’s Employee Assistance Program–which, among other things, helps provide mental and emotional health support to Bureau employees—asked Duffy and another agent from the ERT if they wanted to visit ground zero, since they previously only saw World Trade Center wreckage once it reached the Staten Island landfill.

A few months before 9/11, he explained, he’d taken his young son to the city for a baseball game, after which they passed by the World Trade Center.

Duffy: I wanted to stand and look up. It was very impressive for a 6-year-old. And there was a McDonald's on the corner, and he and I went in there and had lunch, and I remember there was a little table outside, and that's where we ate, and then, you know, we got on the subway and eventually made our way back to New Jersey, ‘cause that's where I was living at the time.

And it was funny, as we're sitting there talking and we're getting [a] brief and I'm looking, and all of a sudden I stop and look around, because it was so unrecognizable. I was almost standing in the exact same spot where my son and I were three months ago having lunch, and here it is, you know, 90 days later, and it's devastated. The McDonald's behind me is a wreck. It's still there, but it's a wreck, but the tables are gone and, you know, right across the street, and I say, "Yep, that's where we walked and that's where we looked at the tower when it was still up."

And that was kind of a powerful moment, too, because I just didn't notice. I looked down, and I was like, “Wow, I'm standing in the exact same spot. How times, how things have changed.”

Oprihory: Duffy said sharing his experience has been a challenge.

Duffy: My kids were young. They don't understand. I mean, they know dad went away for awhile, but they don't really understand.

Oprihory: And bridging that gap, he says, has been a daily struggle for the past two decades.

Duffy: It's very, I guess, sterile. You can read about it in history books. I try not to, but every now and then, I'll see documentaries come out about 9/11, and I encourage, you know, people to look at that, you know, podcasts like this.

I remember as a kid, 'cause I'm into history, I used to read, you know, history books, but then there's some books that are a oral history of World War II, oral history of Korea, you know, where they would talk to veterans. So you would get the less big picture that this unit did this, you'd get the picture that Private Smith was here, this is what he experienced.

So as a kid growing up—and later on—I wanted to read those stories to get the human element.

Oprihory: Duffy praises modern technology and the 9/11 Memorial & Museum as being great ways for people to immerse themselves in history. But he said the best way for younger generations to understand what happened is to speak with people who were actually present at the time of the attacks or in their immediate aftermath. Otherwise, he says...

Duffy: You really can't get a true appreciation, just like I couldn't get a true appreciation of the Vietnam War, and if you have questions, don't rely on the more sterile history books or the internet. Talk to people that have been there or watch interviews, try to personalize it, find something that will bring it home, because the worst thing I think we can do as [a] society is forget.

Horrific events, tragedies, you know, you don't want to be haunted by them, but, you know, just don't forget about it and pick whatever lessons you learn so you're prepared for the next tragedy. Like, we are far more prepared now.

I know when I say “9/11,” I'm looking and these kids were young. They weren't there. It doesn't make them lesser people. It just makes them—they're a clean slate. I need to pass on my experience to them, so they don't make the same mistakes I did. Perhaps they'll make their own mistakes. But if they can learn something from the experience of others, like I did, then do it. You never stop learning until you die. The minute you say, "I know everything," you're lying or you're deluding yourself.

Everyone learns, even you know, us instructors, and, you know, I guess that would be the legacy of all people that've been through a big tragedy is don't forget us and don't forget to learn from what we experienced.

Oprihory: The team members got to pay those experiences forward by training other ERT members on landfill operations and the 9/11 response.

And while the Evidence Response Team Unit offers in-depth training for new and mid-career ERT members alike, Duffy recalls that when it came to September 11th, everything was on-the-job training.

Duffy: We were coming up with processes for handling that much evidence on the fly, based on the fact that there was no blueprint, no template. Since then, the unit and the program has come light years, so it was a challenge. I kind of fell in love with the people I was working with ‘cause they're a good group. That, to me, always helps. You know, you can be in a horrific environment, horrific scene, but if you got people that you trust and you enjoy working with, it makes a bad situation a little bit better and it gives you the confidence that, “ I'm not too sure what I'm doing, but you know what? I know cars. If they tell me what they need, okay, I can figure out the rest,” and then the older heads on the team were showing us the ropes.

Oprihory: The rapport helped seal the deal when it came to him formally applying for a spot on the Philadelphia ERT.

Duffy: I like this, I like the challenge, I like the camaraderie. It was something like, “You know what? I don't want to do ERT just when, you know, a big, horrific event comes. I wanna, you know, do more of this—you know, bring order to chaos, bring closure to victims, and bring something good out of it."

Oprihory: Duffy was officially appointed an ERT member in May 2002. His team lead took special care to mark 9/11 as his first day on the job.

In the 19 years since, he says, he’s gotten the chance to pay forward the kindness and mentorship shown to him as he went on to become the Philadelphia ERT team leader and, eventually, the training director at the Evidence Response Team Unit.

Duffy: When the opportunity came in 2015, I said, you know what? I wanna go to the unit that started it all and pass on what I've learned, mistakes I've made, good decisions I've made, things like that.

Oprihory: His love for the job even inspired him to delay his retirement until 2022.

Duffy: This is how I want to end my career. This is a good group, and I feel that if I can pay it back, and, you know, maybe there's another Tom Duffy out there that when he gets to a scene he's like, "Oh, I remember what that old guy taught me in ERT,” and then 20 years from now, he passes it on. Then that's kind of a good legacy for all of us here in the unit, and, you know, it makes it all worthwhile.

Oprihory: We’d like to thank Tom Duffy for sharing his story with us.

If you were a 9/11 first responder–whether or not you worked for the FBI—and you’ve dealt with physical or mental health issues as a result of that service, you can visit the World Trade Center Health Program web page at cdc.gov/wtc to see if you qualify for free medical monitoring and treatment. The program is federally run by the Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health.

You can also register with the September 11th Victim Compensation Fund at vcf.gov. Anyone—responder or not—who was at the World Trade Center or New York City Exposure Zone in New York, or the Pentagon or Shanksville crash sites between September 11, 2001, and May 30, 2002, can register if they’ve since gotten an illness linked to the attacks.

For more of our coverage marking the 20th anniversary of 9/11, visit fbi.gov/911-20years.

This has been another production of Inside the FBI. You can follow us on your favorite podcast player, including Spotify, Apple Podcasts, or Google Podcasts. You can also subscribe to email alerts about new episodes at fbi.gov/podcasts.

I’m Jennifer-Leigh Oprihory from the FBI’s Office of Public Affairs. Thanks again for tuning in.