'' World Trade Center Plaza Sculpture '' , also called '' Cloud Fortress '' , was a sculpture created by Japanese artist Masayuki Nagare in 1972 , located at the World Trade Center complex at the Church Street entrance to site 's the primary internal 6-acre plaza . Having survived the September 11 attacks , the sculpture was demolished during subsequent emergency efforts to access and clear the site
September 11 attacks
September 11 attacks
World Trade Center Plaza Sculpture