Today at work I was working on assembling a book shelf my boss ordered online. 
While assembling it I somehow managed to snap and break a piece off of it. I have no idea how. I was not using excessive force, I was not doing anything funky.... it just broke off into my hand. I thought I was following the directions correctly but I guess I wasn’t. 
I’m already on thin ice with my job and now I have to turn myself in and tell my boss about the mishap. I am feeling really anxious about it. 
This is my first experience assembling furniture by myself and i was feeling really confident up until the break. 
My boss won’t be back in the office until Monday so I don’t know if I should email her and turn myself in or wait and explain in person. I’m feeling so stupid.