Card wiped when I tried to download files

I was downloading files from my CFast card onto my external hard drive and after about 84.54 GB were downloaded (4 files of 19) my computer shut down and rebooted. When I opened back up the card to download the rest of the footage the card had been wiped. I tried an online recovery software but it came up with nothing. I took it to the largest camera/video rental shop in my city and they could not recover the files either. Does anyone know how I can retrieve the data? I am heart sick as the footage is for a episodic pilot and we do not have the actor availability or funds for a reshoot. Thank you.

Two observations:

1) Driversavers in Novato, CA is the champ at this:

(800) 440-1904
http://www.drivesavers.com/

They are not cheap, but they're among the best in the world at this.

2) Whenever you go into production for something like this, particularly if there could be issues with actor availability and reshoots, you have to get production insurance. This would completely pay for an emergency situation like this.

I have seen situations where film was lost or damaged, sound recordings were destroyed, hard drives crashed, all cases where nobody could have predicted the material would be damaged or lost. This is no different from the bad "analog days" when film could be fogged prior to developing, or the film got badly scratched at the lab (or in the camera). Losing files is basically the modern version of the same problem.

Sometimes the reason why this happens with cards is because the operating system may be trying to write an invisible desktop file on the card just at the moment of the crash, so the signals get splattered all across the card (or drive) rather than in one small confined space. This could be enough to make the card unreadable. Only an expert recovery company could say whether or not the material is still there.

I think it's also cheap insurance to have somebody there on the set, maybe in a van or just in a small truck with a laptop and a bunch of drives, backing everything up to 2 or 3 drives as it's shot. The sad part of life is the one time you didn't back up is the moment you really, really needed it. We've all been there.