SAN JUAN, Puerto Rico (CBS SF/AP) — A new study contends that Puerto Rico saw many more deaths than normal in the three months after Hurricane Maria devastated the island, mostly because of problems getting medicines or medical care.

Researchers surveyed a small sample of neighborhoods and from that estimated that up to 4,600 more deaths than usual occurred. That’s far more than earlier studies have suggested and at least one independent expert questioned the number in the new study, saying it could be off by thousands.

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The official death count from Hurricane Maria is 64, a figure the study characterizes as “a substantial underestimate.”

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The research led by Harvard University was published online in the New England Journal of Medicine. It’s the latest study to analyze how many people died during or after the Category 4 storm that hit the U.S. territory in September 2017, causing more than an estimated $100 billion in damage.

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