Recovered objects offer an outlet to remember the victims of the Sept. 11, 2001, terrorist attacks on the World Trade Center. Sept. 11: In commemoration of the Ninth anniversary of the attacks, the center will only be open to the 9/11 community of families, survivors, first responders, volunteers and local residents. Thru Nov.: Why Teach 9/11? What 9/11 Teaches. Mon, Wed-Sat 10 a.m.-6 p.m., Tues noon-6 p.m., Sun noon-5 p.m.; $10 adults, $5 seniors/students, under 12 free.