**7.7 Pont de Quebec Collapse 1907**

In August 1907 the Pont De Quebec, **Figure 13**, under construction on both sides of the St. Lawerence River, suddenly collapsed killing 75 workers and injuring 11.

*Failure analysis*: The root cause of the failure was an overweight structure for the bridge structural design. The primary contributing factor was an error in the design calculations causing the steel structure to collapse under its own weight. Other

**Figure 13.** *Pont de Quebec collapse in August 1907. CC BY-SA 3.0.*

**Figure 14.** *Pont De Quebec in 2009 [13]. CC BY-SA 2.5.*

contributing factors were lack of review by an independent bridge engineer and clear lines of project responsibility and authority.

Construction resumed in 1910. In 1916 the center span during assembly collapsed, killing 16 works. The cause was failure of a casting used in the hoisting of the center section. The bridge finally opened in 1919 (**Figure 14**).
