Read this and answer the question. If the question is unanswerable, say "unanswerable".

Alumnus Eero Saarinen, Finnish-American architect of such notable structures as the Gateway Arch in St. Louis, Washington Dulles International Airport main terminal, Bell Labs Holmdel Complex and the CBS Building in Manhattan, designed Ingalls Rink at Yale and the newest residential colleges of Ezra Stiles and Morse. These latter were modelled after the medieval Italian hilltown of San Gimignano – a prototype chosen for the town's pedestrian-friendly milieu and fortress-like stone towers. These tower forms at Yale act in counterpoint to the college's many Gothic spires and Georgian cupolas.

Who destroyed the Gateway Arch in St. Louis?
unanswerable