Cracking was noticed near the base on the downstream side of the dam, but it
was not investigated. It is undetermined when these cracks appeared.
Just weeks after the cracks were noticed, on December 2, 1959, a terrible
disaster occurred: the dam failed, killing possibly 500 people.
Little remained of the dam; failure had been sudden and catastrophic. The
dam swung open and released the reservoir water. The dam itself soon
broke away from the abutments and travelled downstream.