Gigi,
In 1999 there was a cable car accident in Grenoble France. 21 people were supposed to have died, most of them astronomer types on their way to an observatory. The cable that carried the car was said to have been 'severed'. Whether it was thought to be on purpose of not was not mentioned in any of the articles I could find here.
But something else was curiously missing from the American media's articles on this catastrophe: The name of the Observatory for whom the astronomers worked. Could it possibly have been the Neuchatel Observatory in Switzerland? Perhaps they were visiting another Observatory...or the Observatory in France they were visiting is somehow associated with theirs'? Perhaps it is even 'their' own facility?
On the surface, this odd hypothesis may sound like a 'stretch', but after the mystery of Diana's death in France, I no longer believe that much of what we see happen around us are accidents. If I remember rightly there was also a very odd train accident in a tunnel in the same area at about the same time.

In any event, is there some way you might find out if French News reported the name of the Observatory that the dead 'astronomers' were associated with? It might help as we put these pieces together.
The more research I do on the PlanetX scenario, the weirder and weirder it gets...
Thanks,
Puzzle