Software :: Startup Volume Is Missing?

The problem began with the Mac running slow and then freezing. Shutting down and restarting (if possible) gave some improvements until finally I got to a point where I could not open up anything from the desktop. I was able to open up my applications from a Firefox image on the desktop. If I placed anything in the applications folder I could open it up as normal. After doing some back up I then began to try different lines of appraoch for solutions:

First: I went into the Disk Utility and verified the disk and repaired permissions. This did not solve the problems.

Second: I booted the computer with TechTool Deluxe. I ran the tests and it found an error on the Volume it scanned---Error -4. I then did a repair of this error which went through successfully. The program then proceeded with another scan and uncovered Error -694. I let it run through the fix process but chose not to save the changes because it eliminated so much of my data. I was hoping I could find another solution before having to resort what appeared to me to be so drastic.

Third: I thought I might try and re-install Mac OS X 3.9 but there was no volume showing to write it to.

Fourth attempt: I tried to boot the computer with my Mac OS X installer CD and then to use disk utility from there. I noticed that my startup volume appeared in the list of options within disk utility but was 'greyed ' out instead of bold faced. I was able to select it and run the Repair function but that failed. I also noticed that when I selected that start up disk it said it was unmounted. I clicked on the mount button but that did not do anything. I then quit installer and it asked me to choose a startup disk, I chose Network Setup since it was the only option. After that when I would try and start the computer I would get a flashing world sign followed by the folder with a flashing question mark. I realize now it was trying to start from that Network Setup, but could not and afterward it could not find anything to boot from and thus the question mark

Fifth attempt: I tried to boot into Safe Mode. I could not. I tried to boot while holding down the Option key. Startup Disk Manager comes on the screen but there are no start up disks to choose from. It appears my Hard Disk has vanished.

Sixth attempt: I then booted again from TechTool Deluxe and ran through the whole process again, but for some reason the repairs could not be completed. I tried several times but the program keeps giving me the same message: "The Volume Structure Rebuild could not be completed"

The best I can figure is that I had a progressively failing hard drive which finally totally gave out. This seems to be the best explanation for all of the problems but I am hoping that someone on here might have a solution for me which I have not discovered yet.