Someone's gonna be mad at me for this but you don't sound tsunami sirens if heading away from the coast and going upland (what tsunami sirens mean) would you take you closer to the danger. It's almost like assuming only one type of disaster will affect a specific area only cuts it until it doesn't. And that after America turned a marshy wetlands into miles of faux-suburbanite grass yard tinderboxes, there should have been dedicated fire sirens there already for decades.

Obviously colonialism changed the American continents forever with a scale and rapidity seldom seen in history (Genghis And The Boys, a couple of the more expansion-minded Chinese dynasties, and the fall of the Russian empire are the closest for my money) - but islands are essentially closed laboratories (see the Galapagos). The effects of the American invasion and occupation of Hawaii are more obvious and pronounced, especially the effects on the local environment. You can only do so much terraforming without consequences.

I know we're all about draining the metaphorical swamp here, but draining actual wetlands and replacing them with grass and large wooden structures is probably not super wise, it turns out.