early on in his novel "players" (1977), don delillo puts forth the thoughts of one of the main characters, pammy -- who works in the world trade center as a brochure writer for a team of grief consultants:

"it was her original view that the world trade center was an unlikely headquarters for an outfit such as this. but she changed her mind as time passed. where else would you stack all this grief? somebody anticipated that people would one day crave the means to codify their emotions. a clerical structure would be needed. teams of behaviorists assembled in the sewers and conceived a brand of futurism based on filing procedures. to pammy, the towers didn't seem permanant. they remained concepts, no less transient for all their bulk than some routine distortion of light."

the wtc towers were also featured on the spine of hardcover editions of delillo's 1997 novel, "underworld."