Imac horror crash

I don’t know what’s going on. Last week my old Powerbook G4 suddenly stoped working because of some hdd error.
Today I told my 1 year old 24” iMac to shutdown and went away. When I returned it was still trying to shutdown but I couldn’t do anything except for resetting. After a reboot the horror was perfect because of this huge ? Symbol on the screen indicating that no hdd was found.
I was near crying
After running hardware test it told me there is an 4HDD/11/40000004 sata(0,0) error. ;(
Disk Utility told me that it couldn’t repair because of wrong disk permission and repair disk permission told me it couldn’t finish because of some unknown error ;(
I’ll now try to solve this with diskwarrior, tomorrow morning I’m going to buy some FireWire cable to try to rescue some of my data via target mode.
Wish me some luck, there’s too much work on it…
why is this happening, is there some kind if hardware destroying virus I’m infected with? A single person just can’t have so much bad luck