OFFUTT AIR FORCE BASE, Neb — Generations of American families have grown up not knowing exactly what happened to their loved ones who died while serving their country in World War II and other conflicts.

But a federal lab tucked away above the bowling alley at Offutt Air Force Base near Omaha and a sister lab in Hawaii are steadily answering those lingering questions, aiming to offer 200 families per year the chance to honor their relatives with a proper burial.

“They may not even have…