An artist’s drawing shows the damage to the Pentagon from the plane’s impact, before a section of the building collapsed.
American Airlines flight 77 created an area of very severe structural damage that was approximately 27 meters (90 feet) wide at its entry point, according to The Pentagon Building Performance Report, published by the American Society of Civil Engineers and the Structural Engineering Institute in January 2003 (p. 28).
The initial impact caused the section of the building that collapsed to shift downwards by approximately 45-60 centimeters (1.5 to 2 feet), at an expansion joint. The slippage is shown at the top of the façade line. (© The Pentagon Building Performance Report)