When you delete a class, you also delete
Any class that has been derived from that class.
Any managed objects that were defined through the use of Administration mode or through an event report.
You can delete any derived or site-defined derived classes but you cannot delete one of the base classes.
To delete a managed class
In Administration mode, expand the Managed Objects node to display the managed classes.
Select the class you want to delete.
Click Delete on the Edit menu.