Several tributes are planned at Pittsburg State University in observance of the 20th anniversary of the September 11, 2001 terrorist attacks. They are all free and are open to the campus and the community. Sept. 9: “Concert of Remembrance” The Southeast Kansas Symphony, directed by Associate Professor Raul Munguia, will perform a 9/11 “Concert of Remembrance” at 7 p.m. on Sept. 9 in the Linda & Lee Scott Performance Hall in the Bicknell Family Center for the Arts, 1711 S. Homer.