Corrupt PST File

A week ago our network lost two of the four hard drives installed. We ended up having to reload the Operating System and restore all company files. This went well except for one small glitch. My Outlook email file came back as being corrupt and when I tried to open it, an error message displayed that it was not a .pst file. I have restored the file from backups all the way back to 6/6/01 and ran the Inbox Repair Tool (Scanpst.exe), but it retrieves nothing. My question is: is there anywayto retrieve or repair the file? And why was the file usable through Outlook until the Network crashed on 8/6/01?