Why would it be devastated if it was designed for it in the first place? Why is it that you think tsunamis destroy every country they hit? French Polynesia

Why would it be devastated if it was designed for it in the first place? Why is it that you think tsunamis destroy every country they hit? French Polynesia has actually been hit by tsunamis before, you just don't hear about it because it isn't eventful. Also Puerto Rico was hit by a strong hurricane, not a tsunami. It was also already 100 Billion dollars in debt and had recently defaulted. Also how do you think neighborhoods of 300 houses already deal with natural disasters? Do you think their only option is to rely on aid from a 'nation state'? They get insurance. It may be a far out idea with many problems that would have to be accounted for but lets use our very best judgement.