The president declares an emergency and direct FEMA to respond.
But that response is way too little:
It's rather unfortunate, but PR is a victim of timing. First came Houston, then FL, and now PR; our feelings on this have become numb. Just look at CNN coverage; it's not even making the main news strip on their website.
Not to mention FEMA is pretty much out of money, so the president can not really do anything without congressional approval on additional funding.
So, like I said earlier, you are trying desperately to make an issue for Trump that is not really his fault.
This is not an excuse for Trump's tweets, but it is just the fact of the situation.
I'd rather pay attention to something about Trump that Trump can really act on, such as how he is dealing with N Korea. I live in Philly, too far for North Koreas missiles, so I'm more perturbed by this. But Chicago is at the outer reach; I would be worrying about other things if I lived there or West.