[TruthInThoughtWordAndDeed]

First the emergency spillway. That will fail structurally within hours of the time water begins flowing over it. Then, when the concrete breaks up, the flow volume will increase and start digging at the dam’s foundations.

[Jimmy Valentine]

I suggest that the big danger is erosion on the emergency spillway, with water eventually going around the barrier. That will cause a catastrophic event that leaves the dam untouched but allows huge flooding.