So I have a basic question, which could interest you:
Supposed I sit there in my room at my computer having fun.
Suddenly the screen goes black because the source which delivers the current to my computer fails (you know, when the fuse box pulls one of these tiny switches, which are for the different rooms)
I hope you know what I mean.
So what could happen to my computer, when it suddenly gets no more current?
well, it definitely stops ....
Now at this point the heads of the hard drive are not "parked" meaning if you jarred the machine it could damage the hard drive.
Second if there was a spike and you are not plugged into a surge protector you could have hardware damage.
Normally I would restart the system and run some diagnostics on the system and hard drive...