It could be any number of things. What kind of clutch do you have? That will make a difference.
A hard line could have cracked, the soft line could have been punctured, the slave cylinder rod could have bent, the clutch fork could have snapped, the slave cylinder could have failed, or the master cylinder could have failed. I would say that the clutch master and slave cylinders are two of the less likely culprits, as they tend to fail gradually over time as the seals wear out.
Check and see if the master cyl. has fluid. Maybe fill it up and pump the clutch (pull it off the floor and pump it with your hand) and see if you can find any fluid leaks.
I think its safe to say that I have had every major clutch hydrolic system problem known to DSMers (except the pedal assembly wearing out), and what you describe can/has happened with any number of failures.
*edit* also, please change your font/color. it is extremely difficult to read