Were the buildings at 270 Park Avenue and 100 East 53rd Street both designed by Natalie de Blois?
270 Park Avenue: 270 Park Avenue (also known as the JPMorgan Chase Tower and formerly the Union Carbide Building) is a high-rise office building located in Midtown Manhattan, New York City. 270 Park Avenue:  It was designed by Natalie de Blois for Skidmore, Owings & Merrill. 100 East 53rd Street:  The building’s architect is Norman Foster.
i don't know