Category
Engineering Failures
Why bridges and dams failed, traced through the official inquiry reports: the sequence of events, the mechanism, and what the rules required afterward.
3 entries
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Silver Bridge Collapse: NTSB Traced It to One Hidden Crack
Why did the Silver Bridge fall in 1967? The NTSB traced it to one eyebar's hidden flaw. Its cause, the two-bar chain, and the inspection rule that followed.
Published
Picture credit
Illustration: From the Surviving Record. Generated schematic image — not a photograph or historical record. © From the Surviving Record, all rights reserved.
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St. Francis Dam: The 1928 Inquiry Blamed the Rock Beneath It
Why did the St. Francis Dam fail in 1928? A state commission blamed defective foundations. Its findings, the flood's timeline and what it asked the state to do.
Published
Picture credit
"The St. Francis Dam" by H. T. Stearns, U.S. Geological Survey — https://commons.wikimedia.org/wiki/File:The_St._Francis_Dam.jpg — Public domain (US: work of a U.S. Geological Survey employee in the course of his duties, not protected by copyright (17 U.S.C. 105); EU: rule of the shorter term (Term Directive art. 7(1)) for a work of US origin with no US term; accepted for federal works by site ruling of 2026-11-01)
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Quebec Bridge Collapse: The 1908 Inquiry Blamed Chord Design
Why did the Quebec Bridge collapse in 1907? Canada's 1908 Royal Commission blamed the design of its lower chords and found its weight had been set too low.
Published
Picture credit
"Pont de Québec vers 1917" by William Notman and Son — https://commons.wikimedia.org/wiki/File:Pont_de_QC_1917_Notman.jpg — Public domain (Canada: photograph made before 1 January 1949 (PD-Canada); US: published before 1931 (PD-US-expired on the file page); EU: a studio work with no individual photographer named on the file page or in the museum record, treated as an anonymous work under the site ruling of 1 November 2026; published before 1931 (PD-US-expired on the file page), so more than 70 years have passed since publication)