I once made a mistake while changing out a circuit breaker in an electrical panel. I used a large metal screwdriver to pry out the breaker.
Predictably, I braced the metal of the screw driver against the metal edge of the panel box, and pried the breaker out. I don't recall whether I slipped, or was inexperienced enough that I didn't turn off the breaker, or if it was a main breaker (which can't be switched off). I somehow managed to contact the front of the screwdriver with something that had power.
The screwdriver and the box were damaged. The screwdriver had the tip burnt off. The shaft had a chunk melted off of it in a small explosion of metal. The side of the box had a gouge where the shaft contacted it.
I was unhurt, but a bit scared. I should have used something non-conductive to pry out the troublesome breaker. Suggestions for non-conductive items: A short length of wood, a fiberglass or wood hammer handle, or some other insulated tool.