We can't say it strongly enough: even when firing a worker, you should make every possible attempt to maintain the employee's dignity.
It's natural for a person being fired to feel resentment toward you and your business. So, everything you do in a termination meeting should be designed to minimize, as much as possible, this natural resentment. We say that not so much out of concern for the worker who is being discharged, but for your own self-protection. It's not good for your business reputation to have ex-employees bad-mouthing you all over town. If customers think that you treat your employees unfairly, they might think that you'll do the same to them.
You'll also want to avoid, as much as you can, the possibility that you might be sued by a disgruntled ex-employee. Most lawsuits in this area are filed because of the employee's feelings, not because the facts of the case are particularly strong. If you can soften the blow to the person's ego, or at least keep from making it worse, your odds of being sued go down dramatically.
Finally, there have been times when fired employees become so distraught that they threaten to harm (or actually do harm) their former boss, coworkers or the business. Treating workers as humanely as possible will minimize the chance that this might happen to you.