This makes sense, but I'd never considered that hurricane names may be retired.

The only time that there is a change is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate for obvious reasons of sensitivity. If that occurs, then at an annual meeting by the committee (called primarily to discuss many other issues) the offending name is stricken from the list and another name is selected to replace it.

Carla, Agnes, Hugo, Andrew, and of course, Katrina are part of the list.