"On that day, a lot of people just ran downtown like everybody else and collected anything that appeared to be an item of evidence," said Elizabeth Rosato, coordinator of the FBI evidence response team.
And Rosato was among those racing to preserve that evidence. She's head of the FBI's real-life version of CSI.
On television, forensic investigators juggle multiple crime scenes, and neatly wrap up cases before the last commercial break. But, in reality, it can take eight hours for an FBI evidence team to take photos, dust for fingerprints and collect evidence from just one car.
"It's great to see it solved in an hour or half an hour, and I like watching that too, but for the most part, it is very, very slow methodical work," Rosato said.
Orr asked: this is basic police work, at grass roots, trying to get the kinds of clues that will help you solve the crime?
"Absolutely, the nuts and bolts of how a case gets solved," she said.
A case, like the terrorist bombing of the USS Cole. FBI evidence experts scraped explosive residue off the belt buckles of surviving sailors, allowing investigators to link the blast to al Qaeda bomb-makers.
That was a victory in what's become the FBI's primary mission counter-terrorism.
Unlike bank robberies and street crimes, terror cases often require evidence collectors to worry less about making a case, and more about stopping the next attack.
"You have to look at the circumstances and what is your ultimate goal, is it a prosecution, or are we racing against the clock to prevent another disaster," Rosato said.
It's a lot of pressure on the 40 FBI agents who make up Rosato's team. And while it's not quite like television…
"Sometimes, I wish it would be that glamorous," Rosato said.
... their work is critical. And the stakes have never been higher.