I think neglect is a major reason, be it due to funding or resource shortages.  It's like buying a well-engineered car and not providing the required maintenance.

Or maybe there are times where mistakes are made during construction or unpredictable geological changes?

These issues should be checked case by case. If you have corrupted individuals involved on different levels or some countries with low capabilities to maintain properly then the risk is high?

I think neglect is a major reason, be it due to funding or resource shortages.  It's like buying a well-engineered car and not providing the required maintenance.

Or maybe there are times where mistakes are made during construction or unpredictable geological changes?

These issues should be checked case by case. If you have corrupted individuals involved on different levels or some countries with low capabilities to maintain properly then the risk is high?