In the heart of Minneapolis, the busy I-35 bridge collapses at the peak of rush hour traffic. As the city reels, the question on everyone's mind: how did an enormous steel bridge fail without warning?

A state-of-the-art high-speed train catastrophically crashes in Spain. In service less than a year, its derailment shocks the world.

Italy suffers one of the worst engineering disasters when the Morandi bridge suddenly collapses. Built in the 60s, it was thought to be indestructible, so what went wrong? And what can failures of a Brazilian Dam, a Manilla high rise, and a building in Jerusalem reveal about its fall? The shocking answers uncover the dangerous flaws that might have doomed these structures from the start.

37,000-feet over Iowa, a DC-10 airplane explodes mid-flight. The quick-thinking pilot crash-lands, saving the lives of 184 passengers. But how could this disaster happen?

In busy downtown New Orleans a high-rise hotel under construction unexpectedly comes crashing to the ground. As the dust settles, the question on everyone's lips: why?