The death count for Hurricane Maria, currently at 64, may be off by thousands

Harvard researchers suspect the official count is off by more than 4,500.
 By 
Mark Kaufman
 on 
The death count for Hurricane Maria, currently at 64, may be off by thousands
Hurricane Maria ripped the roof off of Alfredo Pizarro's house in September 2017. Credit: RICARDO ARDUENGO/AFP/Getty Images

The Puerto Rican government has a list of 64 dead from Hurricane Maria, the tropical cyclone that hit the island in September 2017.

This number, however, is "highly uncertain" notes the National Oceanic and Atmospheric Administration (NOAA). A new study published Tuesday in The New England Journal of Medicine puts that number at an estimated 4,645 — 70 times higher than the official estimate.

"Our results indicate that the official death count of 64 is a substantial underestimate of the true burden of mortality after Hurricane Maria," write the authors, led by researchers from the Harvard T.H. Chan School of Public Health.

NOAA says that the storm, which caused some $90 billion in damage, is the third costliest in U.S. history. But it's the deadliest in over a century, since a hurricane pummeled Galveston, Texas, in 1900, killing more than 6,000 people. Back then, both NOAA and the National Hurricane Center didn't exist, so people were largely unaware of the power brought by the coming cyclone.

Puerto Rico knew what was coming, but the hurricane's wind and downpours ravaged the island's water system and electrical grid. The storm blew down more than 80 percent of the island's utility poles and transmission lines. "Practically all cell phone service was lost and municipal water supplies were knocked out," said NOAA.

While some fatalities were caused by drownings and people being carried away in unprecedented floodwaters, the researchers show that thousands more succumbed during the period between September 20 through December 31, 2017. Around a third of those died due to "delayed or interrupted health care."

In the U.S., official deaths are documented by medical examiners, and in Puerto Rico, specifically, disaster-caused deaths are confirmed by the Institute of Forensic Sciences. This has proven difficult in Puerto Rico, the authors said, because the process often involves taking a dead body to be inspected in the capital. And the storm killed many people indirectly, such as from a lack of medical treatment for chronic disease. It can be challenging for medical examiners to identify such deaths as being cyclone-caused.

Original image replaced with Mashable logo
Original image has been replaced. Credit: Mashable

For this reason, the researchers relied upon a survey of 3,299 randomly chosen homes all over Puerto Rico, asking residents about the causes of death and other factors, like whether or not they were forced to leave their houses. Only 7 percent of households involved did not complete the survey.

Once the surveys were reviewed, the researchers compared the rate of deaths that occurred between September 20 and December 31 in 2016 and 2017, finding that there were more than 4,500 "excess deaths" in 2017 — i.e., deaths that would not have occurred without the devastating impacts of Hurricane Maria.

"These numbers will serve as an important independent comparison to official statistics from death-registry data, which are currently being reevaluated, and underscore the inattention of the U.S. government to the frail infrastructure of Puerto Rico," write the authors.

If the official government report approximates this latest estimate by researchers outside the government, it may persuade current and future U.S. lawmakers to address the aftermath of a tropical cyclone more promptly, and with a heightened awareness of the necessary resources.

NOAA forecasts the coming 2018 Atlantic hurricane season to be "active," with between five and nine hurricane-level storms.

Mashable Image
Mark Kaufman
Science Editor

Mark was the science editor at Mashable. After working as a ranger with the National Park Service, he started a reporting career after seeing the extraordinary value in educating people about the happenings on Earth, and beyond.

He's descended 2,500 feet into the ocean depths in search of the sixgill shark, ventured into the halls of top R&D laboratories, and interviewed some of the most fascinating scientists in the world.

Mashable Potato

Recommended For You
Site to 'check' women's 'body counts' goes viral — and some men are defending it
woman's body inside keyhole with password in front of her


Make your commute count with these 15-minute nonfiction book summaries
Headway Premium: Lifetime Subscription

Is X down? Thousands of users report outage.
hand holding phone with x logo with power lines and workers in background


More in Science
California just launched the country's largest public broadband network
Newsom stands behind a teen on a computer. A group of people cheer and clap behind them.

The Shark FlexStyle is our favorite Dyson Airwrap dupe, and it's $160 off at Amazon right now
The Shark FlexStyle Air Styling & Drying System against a colorful background.

Amazon's sister site is having a one-day sale, and this Bissell TurboClean deal is too good to skip
A woman using the Bissell TurboClean Cordless Hard Floor Cleaner Mop and Lightweight Wet/Dry Vacuum.

The best smartwatch you've never heard of is on sale for less than $50
Nothing CMF Watch 3 Pro in light green with blue and green abstract background

Reddit r/all takes another step into the grave
Reddit logo on phone screen

Trending on Mashable
NYT Connections hints today: Clues, answers for April 3, 2026
Connections game on a smartphone

Wordle today: Answer, hints for April 3, 2026
Wordle game on a smartphone

NYT Connections hints today: Clues, answers for April 4, 2026
Connections game on a smartphone

Google launches Gemma 4, a new open-source model: How to try it
Google Gemma

Wordle today: Answer, hints for April 4, 2026
Wordle game on a smartphone
The biggest stories of the day delivered to your inbox.
These newsletters may contain advertising, deals, or affiliate links. By clicking Subscribe, you confirm you are 16+ and agree to our Terms of Use and Privacy Policy.
Thanks for signing up. See you at your inbox!