Opinion on a falling out with coworker?

[Rebecca]

I'll try to sum this up as short as possible.. I've been working at my new job since September 2012. I work most of my shifts with my coworker K. K and I did become somewhat close, and I told her a lot about my personal life. K always wanted to hang out outside of work, but I usually was busy with schoolwork, and my other CLOSER friends. So bottom line is, Wednesday night I posted to my twitter that I was with a friend, K started blowing up my phone saying I forgot all about her, I'm fake and a bad friend. I tried telling K that I do care about her, and we are friends, but I need to have time for my other friends since I spend a lot of time with K at work. K repeatedly told me I'm a bad friend, I can "have my shitty friends," and told me she doesn't care about me. She continued blowing up my phone with messages like, "F you, you're an asshole. F you and F whatever friendship we had. Bye." At least 20+ messages like those. So why would I respond? Now she is still blowing up my phone, but BEGGING ME for my attention. Almost to the point where I am feeling harassed since she is in upper management.

So, my question.. What should I do? Let her cry it out and continue to ignore her? Tell someone? Why is she so jealous of my friends? HELP.

[Professor Pup]

Either quit this job and cut all ties from this nut case or go to her superiors for help. She sounds very disturbed and needs help asap. good luck.