I would have included the Ford Pinto as a nice contrast to the Citicorp building. When they found out that the gas tanks had a tendency to explode upon impact, it was decided that it would be less expensive to pay off victims than it would be to redesign.

Plus, if you want to stick to bridges and buildings, what about the Quebec Bridge collapse? 75/86 workers were killed. It happened because the bridge itself weighed more than it could support. When a junior engineer reported beam twisting to his superior, he got a response of what amounted to “Must have been like that before we got them; I’m an engineer, so I’m infallible.” That’s why Canadian engineering grads wear an iron ring around their pinky finger (originally made from the iron of the collapsed bridge); to remind them of their responsibility for human life, and to remind them that they aren’t infallible.

I’d also place the Citicorp Tower in this category.

One big engineering blunder not mentioned is the de Havilland Comet–the first commercial jet airliner. Poorly understood engineering data regarding metal fatigue caused by repeated pressurization cycles led to several catastrophic in-flight failures of the aircraft’s fuselage.

Could not find threaded rod long enough,
so instead of using threaded couplings, the project manager approved a change in configuration that doubled the actual
loads at the failure points (which had
attachments that were already marginal).

The change was poorly reviewed
an signed off.

The Mars Surveyor ’98 Program is an example another kind of engineering failure, well-known to every engineer.