The Quebec Bridge Collapse
During construction of the Quebec Bridge in 1907, workers noticed that important compression members were bending. Confusion developed over whether the deformation was dangerous and who had the authority to suspend construction. Work continued while messages passed between engineers at the site and consulting engineer Theodore Cooper, who supervised much of the project from a distance. The bridge then collapsed, killing dozens of workers. The official investigation identified major errors in the designs of compression members, but the ethical failures also involved inadequate checking., divided authority, and failure to respond immediately to physical evidence that contradicted calculations. The central question is what an engineer should do when observations at a construction site suggest that an approved design may be flawed. This case demonstrates that calculations should never be treated as more trustworthy than clear evidence of unexpected structural behavior.