US to commemorate 9/11 as its aftermath extends and evolves  AOLGround Zero Ceremony Marks 18th Anniversary of 9/11 Attacks  The Wall Street JournalAmerica remembers 9/11: Live updates  CNN9/11: How NYC, nation will observe 18th anniversary  New York Post Remembering forty heroes of 9/11  The Boston GlobeView full coverage on Google News