The Quebec Bridge's 1907 collapse killed 75 workers, including Mohawk community members, due to miscalculations. It remains a symbol of engineering lessons learned.
Bridge collapse in 1907
In 1907, the Quebec Bridge collapsed during construction, killing 75 to 76 workers, including 33 members of the Mohawk community of Kahnawake. The disaster was caused by an engineering decision to extend the bridge’s central span without redoing the necessary strength calculations.Engineer’s design flaw
Engineer Theodore Cooper increased the central span by 61 meters, from 488 to 549 meters, to reduce the number of piers in the river and simplify construction. However, he did not oversee the construction on-site and relied on another engineer for the calculations, which contributed to the failure.Collapse and aftermath
The collapse occurred on August 29, 1907, when the southern span gave way into the Saint Lawrence River, taking workers with it. The cleanup of debris took two years, from 1910 to 1912, and the event left a lasting mark on engineering practices in Canada.Second collapse in 1916
A second collapse occurred on September 11, 1916, during the installation of a new span, resulting in 13 deaths and 14 injuries. The fallen span remains at the bottom of the river, but the bridge was ultimately rebuilt successfully in 1917.Legacy of the tragedies
The bridge’s history has influenced Canadian engineering culture, leading to the tradition of young engineering graduates receiving a hammered iron ring, worn on the little finger, in memory of the two tragedies. These rings are not made from metal recovered from the collapsed bridge.Recent restoration efforts
In November 2024, Minister Jean-Yves Duclos confirmed the transfer of the work to the federal government for a symbolic sum of one dollar. Since 2025, a dozen rope engineers have been inspecting the structure, which spans more than 500,000 square meters.Ongoing rehabilitation
A new phase of work is underway this year by PJCCI, with a contract of 19.8 million dollars awarded to Stellaire Construction. The studies are expected to be completed by the end of 2027, feeding into a broad 25-year rehabilitation plan estimated at nearly one billion dollars.Enduring symbol
More than a century after the two collapses, the Quebec Bridge still stands, serving as a symbol of engineering rigor and a cautionary tale of the consequences of miscalculations.
