World Trade Center memorial plaza scheduled to open in 2011 , museum in 2012 . Memorial at Pennsylvania plane crash site also due to open in 2011 . Comment: Watch 9/11 memorials in New York and Washington on CNN.com Live .
World Trade Center memorial plaza scheduled to open in 2011 , museum in 2012 . Memorial at Pennsylvania plane crash site also due to open in 2011 . Pentagon memorial including benches , trees , pools is dedicated Thursday . Watch 9/11 memorials in New York and Washington on CNN.com Live .