Over the weekend, several of my colleagues and I published a very ambitious project called Children of the Fallen: 14 portraits of children whose parents died during the conflict in Afghanistan, the longest war in U.S. history.

But our original idea was far simpler. We wanted to profile just one child, the son of Johnny “Mike” Spann, a CIA paramilitary officer killed in a prison uprising in Afghanistan — and the very first American to die in the conflict. His son was just a baby when he died. My editor, Lynda Robinson, who helms The Post’s local enterprise team, wanted to profile the way his father’s absence had shaped this boy’s life as a way of offering a different perspective on the impact of the war.

I had just interviewed Spann’s widow, Shannon, that spring for a story about the CIA’s Memorial Wall. But when I called Shannon and pitched her on letting us profile her son, she was reluctant. She lives in a new state, works in a different job and enjoys her newfound privacy.

So Lynda came up with a different idea: Instead of focusing on a single child, we’d write short narratives about 14 kids, one for each year since 9/11. In the end, “Children of the Fallen” contains 14 vignettes about 17 kids, whose ages range from 6 to 34 and who live all across the country. (For some years, we chose to focus on a set of siblings.)

It was much harder than we expected to find these families. We have a Faces of the Fallen database​ of U.S. service members killed in both the Iraq and Afghanistan wars, listing their ages and where they were from. But more often than not, the surviving parent had relocated. It was not easy tracking down the right phone numbers.

Nor was it easy to persuade them to participate. Sometimes, the widow had remarried or was dating again, and didn’t want to plunge back into the grief they had left behind. In other cases, the parents wanted to protect the privacy of their children. Finally, after several months, we got our 14 families. Now it was time to interview the children.

It’s one thing to listen to adults speak thoughtfully about death and grieving. To listen to a child try to talk about his or her dad’s death, let alone comprehend how that death happened in the first place, is truly crushing. Does a 9-year-old really know what it means to hear the explanation, “Daddy’s vehicle got blown up?” And as reporters, Steve Hendrix, John Woodrow Cox, Petula Dvorak, Mike Rosenwald and I constantly asked ourselves: How far do you go in pressing an elementary school student or high schooler into detailing his or her devastation?

“Children of the Fallen” tries to answer some of those questions. We hope you’ll read.