A lawsuit filed by the group American Atheists to keep a revered cross out of the National September 11 Museum is being challenged by the conservative American Center for Law and Justice, the Religion News Service reports. The ACLJ filed a friend-of-the-court brief August 20 on behalf of the suit's two defendants, the National September 11 Memorial & Museum Foundation and the Port Authority of New York and New Jersey, which owns the site. The 9/11 museum isn't open yet, but the foundation plans to include the 17-foot cross -- actually two intersecting steel beams found on the site of the former World Trade Center -- among more than 1,000 objects, including fire trucks, an ambulance and the 37-foot "Last Column" left standing amid the wreckage. In the suit filed last year in a U.S. district court in Manhattan, American Atheists claimed including the cross in a museum on public property amounted to an unconstitutional government endorsement of religion and that the presence of the cross would result in emotional injury, anxiety and feelings of exclusion for atheists. Jay Sekulow of the ACLJ said, "The legal arguments of the atheist organization are both offensive and absurd," adding that 190,000 people had signed a petition opposing the lawsuit.