Although this wasn’t the worst, it most certainly could have been, and always comes to mind when questions like this are brought up.

I was on a job site. A half dozen houses were being built simultaneously. I walked too close behind an excavator, which abruptly turned. I nearly got hit in the head by the back end of that thing - which is all ballast and has tremendous mass. I almost got myself sent to the emergency room, and it would have been 100% my fault.

At the moment, I was just glad that none of the guys on my crew saw me pull such a rookie move. I didn’t think about it seriously until I got home that day. That excavator would’ve shattered my cheap plastic construction helmet like it was an eggshell. I could have died.

Nice try, HR.

Worst thing in the office place was when some idiot left their window open in the middle of Winter, temps fell below 0F with high winds, and froze the 2" sprinkler pipes running over their office. Flooded most of the 2nd floor then started running through and raining out onto the 1st floor (and then into the basement). And it happened during covid lock-downs so it was fortunate anyone was even in the building to report it.

My own personal oopsie was checking network cabling in a small room, bent over to check things low and then wandered out to check elsewhere… Then noticed there was a LOT of commotion on the sales floor. Turns out I hit the power switch on one of the phone cabinets with my ass and shut down half the phone lines.

Accidentally hitting reply-to-all on a company wide email and more or less stating that I wanted to be transferred to another team.

There was a new team forming elsewhere, and in fairness, it was a great opportunity in a lot of ways. But… I didn’t get the transfer until another batch of jobs opened a few months later.

That… was a long few months.

The one I still feel guilt over was a time when i found out someone had left an animal trap loaded when they left for vacation. There was a live raccoon in it. I know I shouldn’t’ve carelessly opened it, but I should’ve done something. Even killing it would’ve been kinder. I carry that one with me, to remind me to act when I can. I’m still bad at it, but I try.

The other day I told a customer I could smell gas in her apartment, and even though I feel like a dumbass because it wasn’t a leak (probably lingering smell from them moving an appliance and hitting it on and off by accident), I don’t regret mentioning it. Sometimes I just am going to be an obnoxious jackass about that stuff.

There were three women who were best friends, took their breaks together, etc. And in the Christmas season they wore matching knit sweaters and would walk down the hall side by side so it would read “Ho! Ho! Ho!”

But one day when I was leaving the break room, they approached… and one was out sick. Before I could stop myself I asked “Where’s the other Ho?”

Might’ve gotten a visit to HR from it if I hadn’t looked so shocked at myself.

Missing my first shift at a large retail store because of a misunderstanding. When I showed up the next week, the manager was furious. Not the best start

I haven’t had any big mishaps myself, but I worked in a wafer fab and apparently the person who came in to replace me after I quit, dropped a whole box of wafers like a month into the job. Shit worth like $1M.

That said, massive fault on the company for a lack of better procedures handling those, and afaik the person didn’t even lose the job as it was an honest accident.

Tripped and hit my arm on the maple syrup canning machine that heats a water jacket to 200 f and got a 2 inch diameter blister.

I didn’t actually delete the data but for a solid 1min I thought I had deleted an entire production db of data.

I made a delete then I hit refresh and nothing came. I refreshed again and no records panic started to set in and I refreshed again and still no records. I knew that changes replicated over to our quick backup every min so I picked up the phone and when the guy answered I said I need you to turn off the replication right now I think I just deleted the ministry of health.

After a bit of troubleshooting it turns out the data was fine and my delete worked as intended. The issue was in my client and we checked a few things then gave up. I went for a long lunch after that.

The biggest actual mistakes I’ve done were all caught by a really good manager i had and so I can’t even remember them because they never blew up.

1. Put down a bottle of bleach a little too quickly, a little spurt splashed exactly straight up out of it when it hit the floor and somehow hit me right in the eye. Washed it out in the sink and finished my shift with my eye bright red, instead of, IDK, going to the fucking doctor like I probably should have, because I was young and exploitable.
2. Not me but a coworker: Found a handgun in our customer’s stuff, started messing around with it. You know the punchline. The bullet went through a few walls, cops got called, he made up some story about how it went off on its own while still in the cabinet which no one believed, somehow still didn’t get in legal trouble. He got fired over the phone before he had even left the customer’s premises.
3. Got hired to a startup to fix the intranet slowness, started work as everyone was leaving, instantly fucked the router and broke the network completely for the whole floor, couldn’t fix it for hours and stayed there in a panic until about 3-4 in the morning when I finally figured it out, and fixed the network and the slowness both. Never told them anything except the ending, and they liked my work and hired me full time.
4. Fucked the partition table to the main production server and my boss who was sitting right next to me had a mini panic attack while I reconstructed it from my notes and all the filesystems came back. Keep a notebook, it’ll save your ass.

Pushed to prod

A put a hole in the side of a helicopter that left it grounded for a week.

I accidentally tapped it with another piece of the helicopter. I’m happily working on helicopters that are made of metal now, so no more of that nonsense.

Edit: also, honorable mention because it wasn’t my fault, but I made a helicopter drop an external fuel tank when it took off… by replacing a light bulb. It was on the button that makes the helicopter drop the external tanks, but there are failsafes so it will only do it in the air. Apparently the internal switch got stuck, so the second the weight was off of the wheels CLONK… and a tank was laying on the active runway. Excellent.

Nothing major. In my country when people are fired they are entitled to recieve some money based on how long they’ve been an employee. One time I overpaid a dude who was fired by some 5k USD or so (converting from my local currency) which is nothing major but my boss was pissed. Luckly I just called him and asked him nicely to return the extra money and he did without being rude or anything.

Edit: just as a comparison at the same company once one of our (corporate) clients sent us the payment for a service twice by mistake, some ~200k USD that they had to pay 1x we ended up recieving twice. By comparison 5k is nothing.

1. Alt tabbed once too many times, clicked drop database and yes. Deleted the live authentication DB for America’s Army: Operation video game.

2. Missed the word “add” in “switchport vlan add” on a switch, overwriting the list instead of appending to it. Took out the only connection between two datacenters we were in the process of migrating between. Took me 14 minutes to run to the datacenter, plug in a console cable and fix it.