"Let me know in the comments if you guys have had some close calls"
I haven't worked on my car in 6 months. It's in the garage, along the wall is a fold-out table, or 3' shelving, and not much space in between. A business nearby is getting torn down couple weeks ago, they had an industrial style decor, their cashdesk was half made of 1/8" steel plate. So I offered them scrap value to the demo team to take it, they said naw, go ahead, all yours. It has all of 2 bends in it, 3'x6' for one piece and 1x8' for the other. Probably $800 worth of steel.
An amazing coincidence, because a friend wanted something cut out of a piece of plate that size, about dinner plate sized. No problem, I take it to the garage, but it's already like, 11pm, so I don't want to be doing this outside. I unload the steel between the car and the table, but there's maybe, I dunno, 6 or 8" to spare. Enough now to shimmy between the steel cashdesk and the car, up on my toes the desk comes up to maybe mid-thigh, but otherwise not a lot of room to plant myself as my legs get thicker from there on up obviously.
I want to be space efficient, so I'm trace the pattern at the corner of the sheet. So far so good.
I'd bought a pair of used grinders for $10 total that week from a sketchy part of town. One was broken (probably fixable), the other ran fine and already had a zip disc in it. Super. Might as well fire that one up.
Eye protection, gloves, steel toes, grinder even has the guard on it, good to go.
Among the rules I'm about to break here, beyond not using powertools while up on your tippy toes or too close to your body or anyone knowing where you're working, is "Never trust someone else's consumables". I have no idea how this cutting disc has been used or abused by the previous owner or "owner". Looked fine.
Cut starts okay, but then I feel a shake and first thing I notice is an angry "BRRRRGGGGGG" sound of a locked up motor. The FIRST sign I had that something was wrong, was my brain noticing the sound of a locked up motor. My other senses caught up afterwards.
The motor was making that sound because the trigger was locked on, and, because it wasn't spinning anymore. It wasn't spinning anymore, because it was full of denim, wound-up and bound-up tight. The denim was my jeans. My jeans were ripped from mid-thigh - right where you lit yours on fire - to tight into my groin. My hand is pinned down there too.
I can't access the trigger lock, which is pushed hard into my belt or below it. I try to yank the grinder loose and wisely decide no, it's currently not spinning, let's keep it that way. I flail around with my spare hand a few times until I grab the dangling power cord and rip it out of the wall.
Post-mortem:
Soon as the grinder disc hit the right edge of the sheet metal, the crack it had in it that I failed to notice, caught the edge and launched the grinder. Being on my toes, cutting close to my body, sandwiched between car and desk, cutting with my arms low at thigh-height, I had no bracing against an inward force at the end of my reach. Arms were just a big pendulum. Don't know that it would've mattered, but, the fraction of a second it shoved itself into my thigh, and then the power and edge speed of that split zip disc was however fast it climbed up my thigh like a drag race. 10,000 rpm, 4.5" disc.... 217km/h or 130mph or about 200 feet per second. Which explains why it happened faster than I could notice or react. It only had about a foot to travel between my thigh where it impacted and my groin where it stopped, so, 5 thousandths of a second. An order of magnitude at least below human reaction time.
Untangled the fabric from the grinder, and inspected myself through my now-convertible jeans. Not a scratch. The grinder climbed up my right thigh to my groin, I was fortuitously dressed to the left. Had I not been, wouldn't've been able to tell this story to my grandkids some day, as I don't currently have any (known) offspring yet.
...
I used to volunteer at this place, and the safety instructor lit his hoodie on fire while grinding once. I noticed before he did, and he was at the other end of the shop, leaning forward over what he was grinding. Took him a few seconds to notice, set down the grinder, and pat the fire out with his gloves. He wore it as an item of shame around the shop thereafter, as a reminder.