<human>: Can you provide a brief rundown of the text in within 3 sentences?

I have been working with my co-worker for 1 month. I have been with the company for three years, but recently transferred to a new department. She has been working there for 10 years. On my first day she introduced herself and was very friendly. We have been on good terms since then.

I was working yesterday and apparently mixed up some information when I was speaking to a new client. My co-worker overheard and told our other co-worker to tell me that I had made an error and I was making the company look bad. No problem, I approached her to thank her for catching my mistake. However, when I started speaking she got up and walked out of the office without acknowleding me. I thought it was an isolated incident and decided to leave it for the day.

I was at work again today and my co-worker avoided me. On her way out she passed me and I called out to her to let her know about an upcoming work meeting. She kept walking past me, so I said "Nancy, I am speaking to you." Without even turning around to look at me she yelled *"I hate you."* and walked out the door.

I do not understand what is wrong. Her hostile behavior started right after I miscommunicated to the client, but it was such a minor problem and I immediately clarified. I have to face my co-worker tomorrow, and I need advice on how to proceed. Do I approach our boss first? I don't think my co-worker will even acknowledge me if I do try and talk to her about the issue.
<bot>: co-worker suddenly started acting hostile and told me she hates me. I did nothing to provoke her. Unsure of next steps.