True, but unfortunately it seems like OP's boss doesn't feel this way

It's a little weird that the boss doesn't know the code to disarm the alarm. When my dad was president of his small-medium sized company since he was usually the first in/last out he decided on the 4-digit code. Also, whenever there was a "breach" he'd get a call from the security company alerting him and asking if police should be dispatched (same thing with our home alarm system, actually).

He had the proper instructions. The problem was that the building wasn't empty yet.

Or infamous...

prompting*

Fucking grammar nazi

The FML was published with the spelling error, and later changed. Made me laugh extra hard the first time I read it. As my eyes auto-corrected it, then caught the error.

That was a completely different word you idiot, just because you aren't smart enough to spell doesn't mean you're right.

It's not OP's fault. They didn't know that anyone was still inside. But because it was their first day someone should've been with them just in case.

Well aren't you a douchebag? It was an honest mistake and at least they did lock up the building. The boss should never have left an employee to lock up on their first day. If anyone, the boss did it.

wow I didn't realize that being human and making a mistake is justification to fore someone who's new and isn't quit sure what they're doing. sounds like to me the managers are more to blame in this situation..

Shhh! Troll alert. Maybe if we stay quiet he'll leave.

And that was the last time you fell asleep on the can.

But not the first.

right? sounds like this is more of the managers fault..

no.

How? OP didn't know their boss was still inside the building.