Reddit, whats the worst you've ever fucked up at work, and what did you do to rectify it (if you could)?

You name it, chances are I fucked it up on this project, from promising deadlines I cant make (its in three days), to dropping tables,to loading tables to an incorrect schema, to forgetting to send key documents/re-sending incorrect files.

Right now Im struggling to put together some good language to tell my boss and my clients "look, I fucked up, and we're not going to make that deadline". For what its worth, Im relatively new at this company and had minimal training, but either way I still feel like shit for letting it get to this point and it's really stressing me out.

Having said that, I'm sure my minor mis-step is nothing in the larger universe of workplace blowups.... so what are yours, and how did you soften the blow?