Clues from other disasters are used to solve how the I-35 bridge in the heart of Minneapolis collapsed without warning at the peak of rush hour traffic.

A state-of-the-art high-speed train catastrophically crashes in Spain.

When a Boeing 777 crash-lands at the San Francisco Airport without warning, everyone is baffled.

Italy suffers one of the worst engineering disasters when the Morandi bridge suddenly collapses.

Eleven kilometres over Iowa, a DC-10 airplane explodes mid-flight and the quick-thinking pilot crash-lands, saving 184 passengers; a connection between the infamous Concorde crash, a fatal British skyscraper fire, and a North Dakota train derailment.

In busy downtown New Orleans, a high-rise hotel under construction unexpectedly comes crashing to the ground. As the dust settles, everyone's left wondering why it happened.