Over the years Dunne has urged Sandler kids to pursue careers in finance — but only if they enjoy the field and have what it takes to succeed. He’s never heard one of them say that he or she was getting into the business solely because of their parent. 

“And if they did say that to me, I would tell them that’s a mistake, that they have to lead their life,” says Dunne, who is vice chairman of Piper Sandler and now works out of offices in Midtown.

On a lunch break not far from those 6th Avenue offices, Smith says her interest in finance was piqued by a course she took to fulfill a college requirement. One of her father’s former colleagues encouraged her to apply to Piper Sandler. These days she sometimes passes the plaque in the office that commemorates the 66 people at Sandler who were killed on 9/11, among them her father. She didn’t think she’d end up in the same line of work as him but felt proud to discover “a piece of my dad in me.”

It’s difficult to say exactly how many other children of 9/11 have followed a parent into finance. Kathy Murphy, program director of Tuesday’s Children, an organization for 9/11 families, estimates only a few dozen are second-generation finance workers — a rare cohort united by tragedy. 

Twenty years on, the scale of the losses still stagger. Three out of every four people who worked in New York for the brokerage Cantor Fitzgerald, 658 in all, died when the North Tower collapsed. CEO Howard Lutnick has since rebuilt the firm, and then some.

At the boutique bank Keefe, Bruyette & Woods Inc., 67 of the 171 New York employees were killed when the South Tower fell (KBW was acquired by Stifel Financial in 2013). There aren’t any children of those who were killed currently working at KBW, but several have interned with the firm over the years. At Aon, the British insurer, 176 were killed (Children of three who died now work at Aon).

The list goes on. Morgan Stanley lost 13 employees in New York on 9/11. Bloomberg LP, the parent of Bloomberg News, lost three. Outside Washington, at the Pentagon, 184 people died. Forty were killed when United Airlines Flight 93 crashed in Pennsylvania.

R.J. Hennessey still remembers his mother, Miriam, speaking to his father over the phone after American Airlines Flight 11 struck Tower One.

I’ll try to get out, he told R.J.’s mother. Brian Hennessey, a stockbroker at Cantor Fitzgerald, didn’t make it. He was 35 years old. A police officer delivered Brian’s wedding band to the family’s home in New Jersey. R.J. was four; he’s 24 now.

Sitting on Pier A in Hoboken, New Jersey, across the Hudson from Manhattan, R.J. Hennessey says he didn’t want to grow up to be a stockbroker like his dad. But, much like his father, he has a head for numbers. Today, he’s an accountant at Deloitte.