Hogan and McNevin graduated five months after the attack on Pearl Harbor. Hogan dreamed of becoming a field biologist. Instead, he found himself fighting off frostbite with his hands on a machine gun, flying nearly 27,000 feet above Europe.
Hogan's B-17 fell out of formation after coming under anti-aircraft fire over Germany.
"I assumed all these years that his plane just crashed into the mountains, or somewhere, and they couldn't even find it," McNevin says.
"It is regretted that there is no grave at which to pay homage," the note said. "May the knowledge of your son's honorable service to his country be a source of sustaining comfort to you."
Hogan's parents and two brothers passed away without ever knowing what happened to his body.
But in 1991, a German gravedigger found a metal identification tag from a U.S. soldier. It took 17 years for the U.S. government to get permission from Germany to excavate that site. Investigators turned up the remains of the B-17's crewmembers.
Ed Hogan, a neurologist in St. Louis, never got to meet his uncle, John.
"I'm very appreciative that things have come up, and that we know, and that they've brought his remains back," he says. "I just really wish it would have happened when my dad was still alive."
Hogan is scheduled to be buried in Arlington National Cemetery in August with full military honors.