Study finds more deaths from Hurricane Maria in Puerto Rico than from September 11 or Hurricane Katrina. Nearly as many as the two put together.
Here's the full text of the Harvard study that found an estimated 4,645 deaths in Puerto Rico as a result of Hurricane Maria. Some notes to follow... nejm.org/doi/full/10.10…
The Hurricane Maria study is a statistical analysis of household mortality rates. As the authors note, their figure of 4,645 deaths "is likely to be an underestimate because of survivor bias."
The likelihood of survivor bias influencing their estimate seems high, as the researchers were not able to survey abandoned or unoccupied homes. 
Also: "Persons who were reported to be missing from households, but not known to be deceased, were considered to be alive for our calculations."
In addition to deaths, the study found that nearly 3 percent of Puerto Ricans left their homes after the storm, with nearly half of those leaving the island.
"On average, households went 84 days without electricity, 68 days without water, and 41 days without cellular telephone coverage."
"In the most remote category, 83% of households were without electricity for this entire time period."
"Many survey respondents were still without water and electricity at the time of sampling, a finding consistent with other reports."
Almost a third of households reported a disruption in needed medical services as a result of the storm, with nearly half of those losing access to prescription medications.
"Approximately one third of post-hurricane deaths were reported by household members as being caused by delayed or prevented access to medical care."
"Our estimates also indicate that mortality rates stayed high throughout the rest of the year."
"These numbers ... underscore the inattention of the U.S. government to the frail infrastructure of Puerto Rico."
"The government of Puerto Rico stopped sharing mortality data with the public in December 2017 (our request for these data was also denied)."
