At a Petco, all the Guinea pigs were in a big plexiglass enclosure with a center divider. Boys on one side and girls on the other. An employee decided that all the long haired Guinea pigs should be on one side and short-haired on the other. It took forever to sort them out and all the females were pregnant. -u/PumpkinsDad

Not a mistake necessarily, but I once witnessed our chief accounting officer (and our only accountant; it was a small company) type in values into two Excel cells, pull out a calculator, add the two numbers together in the calculator, and then type the answer in a third cell. She had apparently been doing this for years, with sheets consisting of thousands of rows. I explained how to use formulas and copy them but she apparently forgot because I saw her doing the same thing again months later. -u/zachm26

Tried to cool down hot oil (in a chute, all ready to be emptied) with a nice big bucket of water…..I heard “THOMAS NO” only to turn around and see a GEYSER of hot oil shooting towards the ceiling before it hit and splashed down around him. Nobody was hurt some f*cking how. -u/Ohiolongboard

When I worked construction, there was a guy who showed up with nothing in his tool belt except a small bag of peanuts in one pocket. He didn't stay around too long. -u/Incredible_mango

I had a coworker who was a guidance counselor at five schools in the district. She was supposed to work one day at each school, unless she was called to a school for an urgent case. She would frequently call the school she was supposed to be at, stating she had an urgent case at another school.

One day at lunch she was talking about what was happening in her favorite soap opera. This was before VCRs, and the show aired long before the school day ended. The principal was sitting at our lunch table. He got up, smiled, and told her, "see me when you are done with your lunch." After checking, she hadn't seen more than a few kids per week, for many months. Funny thing is, complaints about her work had gone down in that time. She was a crappy guidance counselor. -u/1Os

The designer, creative director, and head of production all missed that there was an eight-day week on a calendar. We sent 10,000 copies of a useless calendar to a client. Rightly so, they refused to pay for it. -u/atot806

I worked on a golf course during the summer. Area with lots of poison ivy. Two of my coworkers were instructed to weedy a river edge area. If we encounter poison ivy, we either stop what we are doing or go get full suit protection with respirators. These dumbasses were weed-whacking in the thickest poison ivy I had ever seen. No protective suit or glasses or respirator. I roll up and notice what the hell they're doing and point out all the poison ivy everywhere- they were aerosolizing the oil. They both ended up in the hospital on steroids to prevent their death because of the oils they inhaled. -u/Onwisconsin42

I grabbed the arm of an intern once, right as he was about to grab a 00 gauge (the big wires that feed electricity the whole building) bare-handed to move it out of the way to show us a problem behind. It was hot.

He claimed it was fine cause he was only gonna touch one wire at a time. The lead electrician "respectfully" requested said intern be removed from his sight before turning himself into carbon and paperwork. I agreed with this sentiment and had an intern watching OSHA videos for almost 3 days straight as punishment. -u/overengineered

I worked in a paint shop and every time a new chemical was introduced to the shop, I would ask about the hazards. They would tell me that it is a green chemical; there are no hazards. "It's baby safe" they would say. Once when I entered the shop I saw a guy using a new spray. The side of the bucket indicated that it was dangerously poisonous and highly corrosive.

I told him that he should be using a mask and gloves to use that chemical. He said "Don't worry, it's baby safe. They even have a picture of a baby playing in it." Sure enough it did. After seeing the image, I yelled at the guy "This is the baby. He is not playing, he is not swimming, HE'S DYING!" -u/TomoyoHoshijiro

Shut down a critical file server, then lied about it...even after he was presented with the logs that showed it was his user account that initiated the shut down. It's not so much the mistake that he made, but it was when he lied about making the mistake...that was a rookie move. -u/muppetmat13

New guy was dragging two 8000lb rolls of paper through the warehouse. This is against the rules for good reason, anyway, he drove through a door designed for 1 roll, and drug the top roll through the wall. -u/GrandMoffHarkonen

When I was in the Navy, this known dumbass and pathological liar was on armed watch with an M-14 patrolling the topside decks. Literally, all you have to do is walk around for 4 hours with a rifle on your shoulder. This dude came back to the Quarterdeck (main entrance to the ship) WITH NO GUN. He tried to claim it fell off his shoulder and into the water while tying his shoe. How a rifle would fall off your shoulder, pass through your hands that were tying the shoe, and through all three lifelines (like guard rails) is still a mystery. My theory is that he was doing drill team stuff - like tossing it spinning in the air - and lost it that way. -u/not-gandalf-bot

Tried to retrieve his lighter from a deep fat fryer with his hands. boy was that fun to clean up. -u/Mr_Frible

Worked in a machine shop. One of the lathe operators left the bar of cold-rolled steel he was turning hanging out the back. When he turned the machine on, it literally deformed and turned into a freaking helicopter blade that ripped the back of the machine apart, and eventually flew off at high speed. Luckily no one got hit by it. If so, they'd be dead. -u/ribeye256

The office we worked in was shut down due to Covid and the company went 100% remote. A new senior engineer was hired to work directly with our product team and also manage a team of developers. During our company-wide weekly Zoom meeting after he was done presenting for the company he turned his camera off but forgot to put himself on mute. 100+ people heard this man playing Fortnite and talking down about the company to someone else in the background among other things. He only lasted a month. -u/theysocool

I used to work for a landscaping company and over the course of a summer, I witnessed one of my co-workers accidentally set 3 different things on fire (a hedge trimmer, a truck, and himself). -u/RosenBrtt

Poured sink cleaning solution into the ice cream machine instead of the cream mixture and I had to stop them, they then said: "I'm sure it'll be fine, it was only a little." No that would poison people. I had to clean out the whole machine top to bottom and refill it. I ended up throwing away nearly a whole bucket full of contaminated ice cream mixture. I would also like to add that the containers didn't look anything alike, the sink stuff came in big plastic jugs with screw tops and the ice cream comes in cardboard cartons (like orange juice) that you have to cut open. So I don't know how she could have possibly mixed the two up. -u/Yaboijustlikesgoats

Took the wrong coffin to a funeral. Someone else had to drive to the cemetery with the correct deceased on board, and thankfully they made it before the viewing. -u/Shubabi

I worked as a Radiation Protection Tech at a power plant that was re-fueling. My job was to sit outside of a contaminated area and if anyone wanted to take something out of the area (tools, etc.) I had to make sure it didn't have any radioactive particles on it. To do this you wipe the tool with something like a tissue and then hold the tissue up to a machine called a frisker.

If the needle on the frisker goes above a threshold then the tool has to be cleaned or left in the area. One day I come back to relieve a guy who had been sitting outside the area for 2 hours. He tells me there's been no issues and everything has cleared. I look at the frisker, lean over and turn the machine on. -u/LtDirtyBear

One volunteer had no computer experience. We showed her step-by-step how to do her job. She didn't know what a mouse was, how to click on something, etc. We got her up and running. She was pleased with herself, at having gotten the hang of using a PC. Fast forward two hours. Come back to the office and she's in tears "I swear I didn't do anything! There were just fish everywhere all of a sudden!!" Look at the computer. Aquarium screen saver. After her little breakdown, she had to take the rest of the afternoon off. -u/sbenzanzenwan

My coworker at the bowling alley had to walk down a lane where a group of very young children (maybe 4-8 years old) were bowling to retrieve a ball that had stopped in the gutter about halfway down to the pins. When he had picked up the ball my other coworker told him to go walk it back down to the children. However, this guy had it in his mind that it would be best to bowl it back down at the group of small children instead.

Luckily one of the adults with the children was a big muscular guy who was able to stop the ball and pick it up without anybody getting hurt. -u/SamusMcFizz

Annual sales meeting. Brand new guy is seated next to the CEO. He proceeds to put his head down and fall asleep on the table. During the meeting. They woke him up at lunch to fire him. -u/barto5

This was in school but it’s so incompetent I want to put it here. It’s a fairly recognizable story from my school I hope someone finds it. This kid tried to use the teacher's computer to find the answers to our next test. He did it while she was teaching. Science class, so there was a separate room attached where she stored materials and her laptop. So he’s in the room and she’s lecturing to the class. Turns out the computer was connected to the projector display. We’re all watching on the projector, along with the teacher what this genius is doing. Man was in her directory folder typing in “test.” -u/Firemage007

Was making pizza. Guy broke the pizza board(the thing with the handle you make the pizza on and then slide the pizza into the oven) I found the other one and he lost that. So I told him to make pizzas on one of the plastic cutting boards. He put the pizza into the oven on the board and just left it. The board melted. No more pizza that day. -u/allthefishinthelake

One of my reports missed a 9AM meeting and when I asked him why he said “you said the meeting was at 12, not 9!” Of course, I was very confused because the meeting invite said 9 and everyone else on the team knew it was at 9. So he sent me a screenshot of his outlook calendar and it turns out he just had all his sh*t set to the wrong time zone. -u/nokatydidnt92