Do I have a case for defamation?

Nearly two years ago, my former employer forced me to resign or be terminated after 14 years with a spotless record. I never received a performance evaluation in the 14 years I was employed, nor did I ever receive any kind of reprimand or counsel for poor job performance. My job duties were changed, and because I was working at a different work location than I was assigned on 2 or 3 occasions, I was told to resign or be terminated. I filed a grievance with the HR committee to no avail. I filed for unemployment compensation, which my former boss appealed. In the written appeal, he stated that I "put children in danger," by being at a different work site, which is a completely false statement. There were multiple adult staff members providing supervision at the site, and at no time were any children in danger. My unemployment claim was upheld as the employment commission found that I broke no policies of the organization. I have faced challenges in becoming employed in my field, and I learned today that comments made by my former employer prevented someone from hiring me for a job for which I am qualified and for which I was a finalist. I believe the false statement in writing to be defamatory, and that his comments to potential employers are preventing me from becoming employed in my field. Do I have a case for defamation?