Veterans of a World War II low-flying raid on Axis oil fields are gathering in Dayton this week for a 70th anniversary reunion.Those participating in the Ploesti Raid reunion at the National Museum of the U.S. Air Force will hold a public memorial on Thursday, the official anniversary of the raid. Organizers expect nearly a dozen veterans to take part, and survivors of some others are expected. Nearly a third of their planes were shot down. Five Medals of Honor were awarded.