"I kept the general layout of the roof and designed it as two-way folded plate with slightly raised center, to provide for drainage and create arch action to counteract shrinkage and to induce modest longitudinal prestressing by dead load. The elevated curbs around the lightwells had to be prestressed by tendons."
-- Komendant, A. (1975). 18 Years with Architect Louis I. Kahn. Englewood, New Jersey: Aloray. p. 36-37.