Residents along the Pacific Coast Highway (California Highway 1) are cut off from the outside world after a 2017 storm caused the Pfeiffer Canyon Bridge near Big Sur to buckle. Experts reveal how the construction method of the old concrete bridge left it vulnerable to erosion on the steep coastline.

A crane collapse at a high-rise construction project in March 2008 left seven dead on a Saint Patrick's Day holiday weekend in Manhattan. An investigation reveals how a shortcut used while raising the crane left the machine swaying in the wind without proper lateral support.