I suspect a combination of subtle faults. Rebar that may have just barely met code in concrete that was more porous that expected (but still met code). Insufficient accounting for salt spray resulting in accelerated corrosion of rebar leading to spalling of concrete, slightly but significantly greater on the windward side. Combine those two issues with deferred and improper maintenance and you have a building that may only barely last it's entire design life.
Lots of rain, salt air, concrete, steel rebar.
40 years exposure.
I think you’re correct.
This one will be in the civil engineering textbooks as a case study in the coming years.