"Certain groups - those in lower income areas and the elderly - faced the highest risk". "I think the lesson is to anticipate the worst".
Financial instability and a fragile infrastructure made the Caribbean island particularly vulnerable to such weather events, Santos-Burgoa said.
The death toll of Hurricane Maria in Puerto Rico has jumped from 64 to almost 3,000 after an official report was released.
Dean of the Milken Institute School, Lynn Goldman, said: "We are hopeful that the government will accept this as an official death toll". "It's fairly striking that you have so many households without electricity for so long".
The report found that an estimated 2,975 deaths could be attributed directly or indirectly to Maria from the time it struck in September 2017 to mid-February of this year.
The Puerto Rican government had long put the official death toll from Maria at 64 before sharply raising it to 1,427 earlier this month as it was awaiting a more accurate assessment from the independent study from George Washington University. He said the government has improved its communication systems and established a network to distribute food and medicine, but he noted that there are still 60,000 homes without a proper roof and that the power grid is still unstable.
For comparison, the death toll from 2005's Hurricane Katrina - the costliest hurricane in United States history - was far lower, and estimated at 1,833.
There is no national standard for how to count disaster-related deaths.
"The federal government has been, and will continue to be, supportive of Governor Rossello's efforts to ensure a full accountability and transparency of fatalities resulting from last year's hurricanes", White House spokeswoman Sarah Sanders said in a statement.
Puerto Rican Bethzaida Rosado said she didn't believe the government was ready for the storm, and is still angry about the death of her 76-year-old mother. But by reviewing a six-month time frame, researchers found that the storm's lengthy recovery impacted mortality rates for many months, particularly for the island's poorest and older residents.
The researchers found that the risk of death was 45 per cent higher for those living in impoverished communities, and that men over 65 saw a continuous elevated risk of death.
It analyzed death certificates and other mortality data for six months from September 2017 through February 2018. "That's unusual in the US after a disaster".
The report goes on to say that "physician unawareness of appropriate death certification practices after a natural disaster and the Government of Puerto Rico's lack of communication about death certificate reporting prior to the 2017 hurricane season substantially limited the count of deaths related to Maria".
"Many stated that the Puerto Rico Department of Health (DoH) and the Puerto Rico Department of Public Safety (DPS) did not notify them about the CDC special guidelines for correct documentation of cases, on the importance of correctly documenting deaths related to the hurricane or on an emergency protocol for handling these cases", it says. "If enacted, the recommendations of this report could help save lives in Puerto Rico and beyond".