Citicorp Center Vulnerabilities and Discoveries

In 1978, Diane Hartley discovered a critical design flaw in the Citicorp Center, a skyscraper in Manhattan. The building's unique design, with stilts at the center of each side, made it vulnerable to corner winds. Chief engineer William LeMessurier had unknowingly approved weaker bolted joints, which could fail if the building lost power during a storm. LeMessurier secretly reinforced the structure, averting disaster. The public only learned of this in 1995, when a New Yorker article revealed the story.

What was Diane Hartley working on when she discovered the mistake in the Citicorp Center?

• Her master's thesis

• Her undergraduate architecture thesis

• A research paper on skyscrapers

• A project for a construction company

What unique feature did the Citicorp Center have due to the presence of St. Peter's Lutheran Church?

• A glass facade

• A sloped roof

• Stilts placed at the center of each side

• A revolving restaurant

What was the purpose of the tuned mass damper in the Citicorp Center?

• To reduce the building's weight

• To enhance the building's aesthetic

• To counteract swaying from strong winds

• To support the building's foundation

Why were corner winds a significant threat to the Citicorp Center?

• They were more frequent than other winds

• They were stronger than winds on the broad sides

• They were not considered in traditional safety calculations

• They could cause the building to sway excessively

What change in the building's construction increased its vulnerability?

• Use of a lighter exoskeleton

• Replacement of welded joints with bolted joints

• Addition of more windows

• Reduction in the number of columns

What was the probability of a storm strong enough to threaten the Citicorp Center hitting New York City each year?

• One-in-twenty

• One-in-ten

• One-in-fifty

• One-in-sixteen

What action did LeMessurier take after discovering the building's vulnerability?

• He publicly announced the issue

• He secretly reinforced the building's joints

• He redesigned the entire building

• He ignored the problem

When did the public learn about the potential disaster at the Citicorp Center?

• In 1978, during the reinforcement

• In 1980, after the reinforcement

• In 1995, through a New Yorker article

• In 2000, during a documentary

What event helped keep the reinforcement project a secret?

• A major sports event

• A political scandal

• A city-wide blackout

• A newspaper strike

Who was not given credit for discovering the building's flaw until much later?

• William LeMessurier

• The construction company

• The city officials

• Diane Hartley