The "Hope for Healing" theme was used in 2002 in remembrance of the September 11 terrorist attacks three months earlier: 195 of the ball's panels were engraved with the names of countries and emergency organizations that had taken casualties during the attacks, and the names of the World Trade Center, The Pentagon, and the four flights that were involved in the attacks. In December 2011, the "Hope for Healing" panels were accepted into the permanent collection of the National September 11 Memorial &amp; Museum.