How one design flaw almost toppled a skyscraper

In 1978, Diane Hartley was writing her undergraduate architecture thesis when she made a shocking discovery. After weeks of poring over the Citicorp Center's building plans, she'd stumbled on an oversight that threatened to topple the 59-story tower into one of New York City's most densely populated districts. Alex Gendler digs into the skyscraper's potentially deadly mistake. [Directed by Nicholas Paim, Alopra Studio, narrated by Jack Cutmore-Scott, music by Stephen LaRosa].