Koolhaas responded to that awkwardness in typically brash fashion. Instead of trying to work around the presence of the El, as his competitors for the job did, Koolhaas turned it into the centerpiece of his design. He wrapped the tracks inside a 530-foot-long concrete-and stainless-steel tube that's embedded in the roof. The tube helps dampen the sound of the train inside the student center and gives El riders the sensation that they're speeding right through the building. From the outside, the tube also appears to crush the boxy form of the building itself—a not-so-subtle challenge to Mies, for whom flat-roofed, single-story boxes were a signature style.