Who Is Responsible If the Trustee Abandons His Duties?

My trustee claims that I insulted him in an email, which I did not. I believe he does not want to have to file income taxes on a special needs trust and used this as an excuse to bow out of his role as trustee. He informed me that he has taken all the files relating to the trust and sent them back to the trust's creator. I don't know if he did this or not because the trust's creator is my father (and also the trustee's father), and he is 92 and quite ill and was not well enough to talk on the phone.  What can I do? If the trust becomes delinquent in taxes or other matters, who is responsible for the financial loss?  I am really not capable of straightening this out myself.