On December 2, 1959, the Malpasset arch dam in southeast France suddenly failed, flooding the valley down to the sea, causing huge destruction and more than 400 casualties. Built from 1952 to 1954 for water supply and irrigation, filling of the reservoir was delayed five years and the failure occurred following a flash flood of the river the dam was closing. Post failure studies and expertise during a trial revealed poor field investigations on a micaschist rock foundation crisscrossed by faults, and poor management of construction of the structure. The failure was ascribed to uplift, moving a rock dihedron defined by a conspicuous fault and a tear along foliation. This paper shows that, in addition to the many traps listed by previous investigations (mostly geological and geotechnical), the human and organizational factors can also shed a new light on this catastrophe. Keeping lessons from Malpasset alive and increasing the knowledge about this case is relevant since worldwide, after the catastrophe, not only did new regulations on dams appear but also both fields of geological engineering and rock mechanics were developed. Thus, consciously or not, every geological engineer or rock mechanics specialists is somehow, a descendant of this case.