Progressive collapse

A building undergoes progressive collapse when a primary structural element fails, resulting in the failure of adjoining structural elements, which in turn causes further structural failure. A building undergoes progressive collapse when a primary structural element fails, resulting in the failure of adjoining structural elements, which in turn causes further structural failure. Since the resulting damage in a progressive collapse is disproportionate to the original cause, the term disproportionate collapse is frequently used in engineering to describe this collapse type. The first date-recorded instance of the term pancake collapse being published in lieu of 'progressive collapse' occurred in the August 10, 1980, edition of the New York Times. Fire Chief John Connelly of the 19th Battalion explained that the apartment building, which they responded to in the Bronx, had been weakened by fire to the point that all floors had begun to pancake down on one another. ''It was a pancake collapse.' said Chief John Connelly of the 19th Battalion. 'The entire building was flaming and it went down to the ground.''