So how the hell did that happen?

So last night I came back from my girlfriends room to find my room mate screaming at his laptop. He couldn't get it to start. He shut it off because it froze and now it wouldn't work. So after trying to get it to work and to no avail we put in the OS repair disk. It scans the hard drive and comes up with the list of OS's on his computer. Well there was nothing on the list. the OS was gone! It freakin wiped itself! Then we tried to  recover the OS with the reinstall disk. Nothing. Didn't work at all. The bloody hard drive fried itself. How the bloody hell did that even happen? Some how him shutting off the frozen laptop made it fry the hard drive. Wow... Just wow...