The memorial commemorates the victims from the town of Zabalj, Serbia who were slain in 1942 during a raid by the Hungarian Axis forces. Being unfamiliar with this action I went off to Wikipedia to find out more information. The entry for Zabalj mentions the raid and includes the following information:
“During the Hungarian Axis occupation, in 1942 raid, 666 inhabitants of the town were murdered”
-Wikipedia entry for Zabalj
That’s an… oddly specific number of casualties.
Sometimes the adventure seeds write themselves.