World Trade Center towers / Memorial Day / America's transportation system / Washington / D.C. This monument / /
Holiday
Commonwealth Day of Puerto Rico / Memorial Day / /
IndustryTerm
law enforcement officers / sworn law enforcement officers / transportation industry / transportation / law enforcement / unprecedented travel / transportation systems / transportation system / sound infrastructure / /
Movie
World Trade Center / /
Organization
Congress / United States Congress / Police Service / Citizen Corps / /
Person
GEORGE W. BUSH / /
Position
fallen officer / President / President of the United States of America / /