“I didn’t even find out that he was on that mission until I was 10 years old and read some old news clippings in my grandmother’s attic,” Tom VanKirk told the AP in a phone interview Tuesday. Like many World War II veterans, VanKirk didn’t talk much about his service until much later in his life when he spoke to school groups, his son said. He later moved from California to the Atlanta area to be near his daughter. Then he went to school, earned degrees in chemical engineering and signed on with DuPont, where he stayed until he retired in 1985. VanKirk stayed on with the military for a year after the war ended. It seemed a lot longer than 43 seconds,” VanKirk recalled. “I think everybody in the plane concluded it was a dud. They counted - one thousand one, one thousand two - reaching the 43 seconds they’d been told it would take for detonation, and heard nothing. They didn’t know whether the bomb would actually work and, if it did, whether its shockwaves would rip their plane to shreds.