BREAKING: the Puerto Rico govt, tonight, is submitting a report to Congress that states: “On June 13, 2018, the Government of Puerto Rico revealed that there were 1,427 more deaths in the four months after the hurricanes than normal (based on the previous four years)...”
— David Begnaud (@DavidBegnaud) August 9, 2018
Most deaths in the aftermath of any sort of natural disaster aren't easily directly attributed to the event. Most aren't "tornado blows over tree which lands on man's head" or "man drowned in floodwaters during hurricane" type things. The only really to get at how many deaths were really attributable to the event and its aftermath (lack of power and water leading to heat-related deaths, for example) are to measure the number of deaths relative to the "normal" amount during a similar time period.