In 2002 we had a holiday in Antigua courtesy of
lastminute.com, and as we were landing at the airport and looking down at the houses, it looked like a bomb had hit it! We learned later that was from when the island had been hit by a Hurricane a number of years before.
I learned a lot about weather in the Caribbean that holiday and found out that days could be cloudy and wet even there.
You might be right about the prefab idea, a kind of super Anderson shelter from the last war.
The one noticeable thing when looking at the damage done, is that the hotels for the tourists although in prime position on the beach front usually remain intact though. I bet the building specs are much higher than the ones for the rest of the island.