I didn't even know that, and I don't think I know anyone who knew that. It was in the French part though, stuff like that wouldn't be seen in the Flemish part

. I've actually been to Eupen (where it happened) once, on a schooltrip and they didn't mention it. I just looked up the city site of Eupen, and there's no mention of it in the history.
I say it was the US... Or probably the Chinese

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Here are the video's: