15 Years After 9/11 Attacks, Americans Remember

iconic – adj. widely known

fortress – n. a place that is protected from attack

crumble – v. to break something into small pieces, fall apart

rubble – n. broken pieces of stone, brick, etc. from walls that have fallen

skyline – n. the outline of buildings against the sky

twin – n. one of two exactly the same

magnificent – adj. very grand

commemoration – n. something that honors an important event or person in the past

plaster - n. a web substance that hardens when it becomes dry and that is used to make smooth surfaces