This reminds me of the time I happened to be at a warehouse where an industrial motor control panel was being decommissioned. In the center of the panel is a large breaker, which was dutifully opened (ie powered off) before work commenced. But bizarrely, someone in the past managed to tap power from the supply-side of the breaker for some sort of monitoring sensor inside the panel. So when that circuit was cut through, there was a loud bang and the overhead lights went out.

No one was injured, although everyone was jumpy from the inadvertent light-and-sound spectacle. And a set of cutters gained a 12 AWG-sized (approx 4 mm^2) hole.

I may have misremembered some details, but my takeaway as a non-electrician was to 1) never assume a breaker handle at face value, and 2) don’t assume the prior person made sane choices.

forgot to check the breaker?

I swear I heard it when I saw the picture. I’m not an electrician, but that’s why I always call electricians instead of doing it myself.

Steel is real, not all wire is created equal. Someone borrowed the soft jaws and chewed the wrong chow.

That looks a bit deep to grind, but maybe. I grind the back face of my higher end diagonals to sharpen and extend their life.

You made a small notch to strip cables ? LOL

You lent them out?

You tried to bite the cable, and the cable bit back?

involuntary welding

You found the breaker.

oopsie happened

You didn’t LOTO

You changed the strings on your guitar.

The dog got a hold of them.

There was a hidden layer of concrete in your steel cables

Forgot your strippers and made due anyway