looks like you were using the computers on-campus. I don't know your school, but my school always reminds everyone of making additional copies for important documents.
just want to point out one issue:
If you knew you were using a shared-computer, you should have known that you need to have more than just one copy of all the files saved on the shared-computer. I hate to use the word, but those judges keep using words like "a reasonably prudent person in such situation would ...blablabla."
I don't know much about computer. but from my own experience, suddent and unpredicatable crash of computer system can almost be categorized as "common and inherent danger" -- probably will be very difficult for you to prove that somebody hacked your account and deleted all your files with malice.
I agree with Mr. CAT; remedy the situation first, as much as you can.