I too could add:

Stood on stone countertop to hang fixture, end up on floor with said stone countertop.

I could go on, and on... Over fifeteen years worth.

On crew ^%&*up's:
No concept of level, square or straight.
Dropping light fixtures, cracks large picture window in process.
Drill through finished floors.
Lost neutrals setting computers a blazin'!
Service side short, knocks out whole neighbor hood.

And thats just one guy.... (No longer employed)

Mark Heller
"Well - I oughta....." -Jackie Gleason