That’s the single most frightening detail about the disease I’ve encountered in my reading. There are tragic details, such as people dying alone in isolation, away from their families. There are grim details, like the descriptions of physical suffering some endure. But the scary element is the speed with which some patients deteriorate, from seemingly fine one minute to critical the next. Even doctors and nurses are shocked by it. Many of these dead-at-home cases probably involved people who thought they were doing well enough under the circumstances, with the disease running its course, only to expire suddenly when it took a turn.

Whenever I read about another sudden death I come away wondering when, precisely, people are supposed to seek hospital care. If death can sneak up that quickly, with even medical professionals unprepared for its onset, then everyone riding it out at home with “mild” symptoms is tempting fate by not going to the ER.

Anyway, NYC knows that it’s been undercounting its dead. Until now, anyone who died without testing positive beforehand wasn’t treated as a COVID-19 death, never mind the gigantic surge in unexplained dead-at-home cases. But that’s changed.

New York City, already a world epicenter of the coronavirus outbreak, sharply increased its death toll by more than 3,700 victims on Tuesday, after officials said they were now including people who had never tested positive for the virus but were presumed to have died of it.

The new figures, released by the city’s Health Department, drove up the number of people killed in New York City to more than 10,000, and appeared to increase the overall United States death count by 17 percent to more than 26,000.

The numbers brought into clearer focus the staggering toll the virus has already taken on the largest city in the United States, where deserted streets are haunted by the near-constant howl of ambulance sirens. Far more people have died in New York City, on a per-capita basis, than in Italy — the hardest-hit country in Europe.

“Probable deaths were recorded as people who did not have a positive lab test for Covid-19, but did have Covid-19 or something similar listed as the cause of death on their death certificate,” says Politico of the city’s new method. Note well: “Probable deaths” here does not account for all “excess deaths” in New York recently. The city knows from its historical records roughly how many people are expected to die between mid-March and mid-April every year. There’s an official number of COVID-19 deaths affecting that number this year, and a number of probable COVID-19 deaths, and a number on top of that in which the deceased probably didn’t have the virus but may have expired for reasons indirectly related to it. For instance, if someone had chest pain but decided not to risk a trip to the hospital for fear of being infected and they ended up dying at home, that wouldn’t count as a probable coronavirus death. But it should count as an excess death, a case where the patient probably would have lived but for the epidemic.

Pro Publica is finding lots of uncounted probable COVID-19 deaths in other American cities — as well as a decline in 911 calls in others, possible evidence that people are more reluctant to go to the hospital now.

In Detroit, authorities responded to more than 150 “dead person observed” calls in the first 10 days of April. It was around 40 during the same period for the past three years, according to city 911 call data. Almost all of the incidents in this year’s period occurred in areas where the median household income was less than $45,000, census data shows. Lower-income areas have been particularly hard hit by the coronavirus…

In other parts of the U.S., 911 calls for medical assistance have dropped. In Seattle, an early epicenter of the pandemic, data shows that EMT and paramedic calls dropped by more than 25% in the first 10 days of April compared with the same time frame last year. It’s unclear how much, if any, of that drop is due to people being fearful of interacting with the health care system.

I keep thinking about that recent op-ed written by a cardiologist wondering where all the heart attack victims have gone lately. There’s been a steep decline in critical cardiac patients at his hospital and he can’t explain why. Best guess: Some were infected by coronavirus and dropped dead at home from the disease before they could call 911, while others who weren’t infected may have persuaded themselves that their cardiac symptoms weren’t serious enough to warrant a risky trip to the ER and ended up miscalculating fatally. The heart attack victims, some of whom would have been saved in normal times, have gone to the morgue.

This arresting graph demonstrates how much more dangerous COVID-19 is relative to the flu:

https://twitter.com/tnajournal/status/1250143135398838279

In New York it looks like this:

When people warned in February about exponential growth, it was not obscure math. It was straightforwardly looking at the curves in every other country and saying we would see same the same shape here. And we have. https://t.co/SVNscTHZrQ pic.twitter.com/0PftsPru2o

— Ari Schulman (@AriSchulman) April 14, 2020

The good news, per Nate Silver, is that the percentage of positive tests relative to total tests in New York State lately suggests that not only have they flattened the curve, they’ve bent it downwards. The rate of transmission may have fallen very slightly below 1, which means cases should begin to shrink very gradually. It took a lot of economic pain to make that happen. It’ll take much more to get the number of daily deaths down to double or single digits so that the city can “reboot” with better surveillance and testing in place.