Are you talking about the Passage du Gois? (It's in the Baie de Gascogne AKA Bay of Biscay & connects to a little island (Ile de Noirmoutier). It was like the first day or so and took out a whole bunch of guys. That was what, maybe five or so years ago? Definitely to go in the "What were we thinking?" section of the Tour organizers' curriculum vitaes. The crash that still gets me crazed just thinking about it though was probably the first TdF I ever saw many many years ago: a dumb-as-a-stump gendarme, a COP for pete's sake, jumped in front of the riders to snap a picture and took out a couple of guys (one of whom was Laurent Jalabert I think!) I am surprised, though that in dog-mad France we don't see more problems with dogs on the road. THEY are what always seem to get me! And kids. (I broke a couple of ribs trying to avoid crashing into a couple of clueless kids. I love both (dogs & kids) but not when I'm on my bike.They scare me to death when I'm riding.
That's it!! I could not remember the name of the thing. Thanks for posting it!