I'm not sure if it will be possible to recover these audio files purely in Vegas alone, but if you have Sound Forge (or some other audio editor) it should be fairly easy.

The problem is that when Vegas records the audio it stores the audio data normally in the .WAV (or .W64) files, but until the recording ends Vegas doesn't know how long the files are and so it can't complete the files by writing the correct length into the appropriate place in the header of the files. Because Vegas crashed before the recording was stopped, the length (and possibly some other items in the header of the WAVs) is still set to some temporary bogus value, probably zero.

The solution is to open these files in an audio editor (e.g. SF6) which can open RAW audio data files. If you open the data files as RAW you will need to tell SF the correct values for the bit depth (24-bit in your case presumably), clock rate (48kHz or 96kHz presumably) and whether they are stereo or mono, etc. Once you have told it this information SF will open the file, treating the entire contents as though they are audio data. There will be a glitch at the beginning (where the header information is being erroneously interpreted as audio data*), but you should find that apart from this glitch that you can easily chop off, you will have successfully recovered the audio from the file. You can then save each of these recovered audio files as a normal WAV file and you should then be able to open them in Vegas and re-assemble the multi-track recording correctly.

Best of luck.

Mark

*Actually, if you want to be a bit cleverer you can specify how many bytes to skip at the beginning of the file to avoid this glitch, but it helps to have a hex editor to look at the beginning of the file and a knowledge of the internal structure of a WAV file to see just how big the header is, so you can tell it the correct number of bytes to skip. It's probably easier just to accept the glitch and then chop it off.