I currently work for a non-profit organization in Tucson, AZ known as the Hermitage Cat Shelter. As of late, work conditions have become increasingly hostile, and it's to the point where most of us are feeling extremely intimidated when called to speak with our director. Just recently, we signed a statement explaining why we felt work conditions were intolerable; along with separate Letters of Grievances from all of us. One of my co-workers was just fired today; and though she was not given a reason, we all feel that it was a direct retaliation to the letters. Now that the situation is explained, here's my question:

Is it illegal for an employer to terminate the employment relationship of an employee as a direct result of submitting a document stating that he/she feels that their work environment has become hostile and uncomfortable?

Was this complaint part of a approved grievance procedure, or was it merely a private letter telling them everything you though was wrong.

And I guess they felt if you all thought it was so bad to work there, you may just be happier somewhere else,

Can a company fire an employee for complaining, yep, now why is it hostile, because the boss is mean, is there racial issue, is there sexual issues ? If the reason was for a protected class of problem, then no.
But can a company fire someone if they feel the complaint is pointless and want to merely clean house of complaining employees, happens every day