9/11 Flag Memorial by Ruby Wallau September 11, 2019 Share Facebook LinkedIn Twitter A student plants a flag in memorial of the 18th anniversary of the 9/11 terror attacks at Krentzman Quadrangle. Photo by Ruby Wallau/Northeastern University A student plants a flag on Krentzman Quad to honor the victims of 9/11 on the 18th anniversary of the terrorist attacks. Photo by Ruby Wallau/Northeastern University