TIFU by unintentionally telling a cleaner she was going to die

Our office enjoys a good immature joke, but I didn't expect it to go this far.

A co-worker with a great sense of humor tested positive at home and called to say he was coming to pick up his stuff from his desk, and that he'd mask up etc. Quickly before he came, I created a sign for his door with the words:

THIS OFFICE IS INFECTED WITH COVID. IF YOU STEP INSIDE YOU ARE GUARANTEED TO DIE.

To make it extra ridiculous, I included a clip art-esque image of a happy smiling skeleton peeking out from behind a casket lid.

He came in to collect his stuff, he laughed and asked, "Who the fuck made that crazy thing?" and collected his stuff. Hours later, I put the sign on his desk, facing away from the corridor (you'd need to be behind his desk to see it).

That was last Friday. Fast forward to this week...

On Monday, our office manager notices nothing was cleaned/trash wasn't emptied on Friday. She thought nothing of it, we value the building's cleaning staff and she figured the lady must have been sick and taken Friday off. No big deal.

For context, we are one down from the top floor of the building, and the cleaner typically goes top-to-bottom. There's five floors beneath us.

Hours later, the cleaning company boss walks in, interrupting his vacation time off, to come in and see us.

He asks about the "Covid situation" in the office, and says he was told our office had been declared "contaminated" by the local health authority, with "fatal covid".

Turns out the cleaning lady saw the sign on Friday, burst into tears, locked her cart away and ran home having only cleaned one floor of the building. She then spent all weekend upset and in tears thinking she was going to die. She told the boss Friday who missed the message and when he reached out to her Monday, she announced she's refusing to come back to work because of the "contamination".

She believed my sign was an official sign from the local health authority, which is totally beyond me, because the wording was ridiculous and the clip art picture of the smiling skeleton in the coffin couldn't have made it any more obvious it was tongue-in-cheek. If I'd added the local government logo then perhaps I'd be to blame, but I didn't.

The boss was shown the sign and agreed it wasn't real, but did ask we don't do "things like that" any more, as it scares people.

He now has a staff member who walked off the job Friday, spent all weekend upset about her impending death, and is refusing to come back to work.

I felt pretty bad, but can't feel bad for her stupidity. Either way, I fucked up!

TL;DR - I put up a joke sign about guaranteed death due to Covid in our office, and a cleaning lady took it seriously and walked off the job.