Massive Engineering Mistakes

Episode 9 (2x9)

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The Big Dig in Boston was a massive infrastructure build that would take a freeway that was blight on the city and put it underground, but a tragic accident raises concerns about its safety. A new bridge in Wales collapses before it is even completed, is it an issue with design or construction? A dam in Spain collapses, devastating a region. A Milwaukee bridge begins to sag and debris is seen falling from it without any warning.