On Tuesday night 18 families of critically ill children in the area were invited to a special dress rehearsal performance of “The Nutcracker” through the Casey Cares Foundation, a Columbia-based organization that hosts events for families of sick children. The nonprofit aims to create special moments of joy for local families dealing with financial and emotional hardships in environments that are accommodating to their particular needs. The classic Christmas dance show, produced by the Ballet Theatre of Maryland, allows families to enter late and come and go as they please. Ballet Theatre of Maryland has been donating tickets to its performances since 2007.