cable street blues

I have got some pretty heavy duty equipment for unscrewing stuck screws. I have unscrewed massive rusted in beasts with centuries of experience of resisting. I have unscrewed the impossible from nasty tight corners, down grim dank holes and from high ceilings in lofty towers. So - when I saw this rather odd plank dividing up the kitchen ceiling for no apparent reason I decided to unscrew the generous 17 screws and get rid of it. I couldn't undo ANY of them. grunt, groan, strain,swear, heave, swear.
So - I figured I could saw near the screws and work from there. 2/3 of the way threough the sawing and BANG - sparks saw teeth arced off, and the ancient fuse box didn't blink.
So- Lift floor boards, discover cable running in a channel in the plank under the ceiling and the old wooden spacers. Trapped. Two hours later the cable is replaced properly with a whole new one , floor boards back and plank still there. There is no electricity in that cable now so I will get the bugger tomorrow. The hole in the cable? That is where somebody managed to screw a pulley right through it without electrocuting themselves.
How they didn't fry . . . .