Trump, in addition to waiting 13 days to go to PR, - which the fricken addled bumbling idiot didn't even know was part of the USA despite being from NYC himself (which has more PRs living in it than San Juan does) - stalled aid relief after the hurricane, and basically didn't want to send them any.
He also tried to minimize the reported amount of damage and impact from Maria - the biggest natual disaster in US history - as well as the number of deaths.