A new study has estimated the death toll from Hurricane Maria and its aftermath to be more than 4,600 at least:

A new Harvard study published Tuesday in the New England Journal of Medicine estimates that at least 4,645 deaths can be linked to the hurricane and its immediate aftermath, making the storm far deadlier than previously thought. Official estimates have placed the number of dead at 64, a count that has drawn sharp criticism from experts and local residents and spurred the government to order an independent review that has yet to be completed.

The Harvard findings indicate that health-care disruption for the elderly and the loss of basic utility services for the chronically ill had significant impacts, and the study criticized Puerto Rico’s methods for counting the dead — and its lack of transparency in sharing information — as detrimental to planning for future natural disasters.

The official count was always far too low, and this was known in the weeks and months following last year’s hurricane. Deaths from the hurricane were officially recorded only after the bodies had been seen by the medical examiner, so there were bound to be many that were never acknowledged in the official record. The Harvard study notes that this is one of the reasons why the official count is so low:

The Harvard researchers reported that there are several reasons the death toll in Puerto Rico has been drastically underestimated. Every disaster-related death, they said, must be confirmed by the government’s Forensic Sciences Institute, which requires that bodies go to San Juan or that a medical examiner travel to the local municipality.

Back in October, there was a report that there were more than 900 bodies that were cremated in the wake of the hurricane that had never been examined. If the study’s estimate is even close to accurate, that was just a fraction of the overall death toll. The conservative estimate of 4,645 deaths is a measure of how truly catastrophic the hurricane was for Puerto Rico and how woefully inadequate the response to it was. We knew that Puerto Rico was going through health and environmental crises following the hurricane that devastated the island, and we could see at the time that the response was slow and insufficient, but now it appears that things were much worse than we knew.