No American elected official has said as many dangerously irresponsible things about the coronavirus as President Donald Trump. But we would be remiss if we let local officials, including those who have led well since, off the hook for their own early downplaying of COVID-19.

We say this not to wag a freshly washed finger; the pandemic has been a painfully humbling learning experience for this Editorial Board, too. We say it to establish how widespread and potentially costly was the early underestimation of the pain and death COVID-19 might cause in New York City.

On Feb. 26, before the virus strained the city’s hospital system nearly to the breaking point, New York City Mayor Bill de Blasio said, “We’ve got a long time to ramp up if we ever had anything like that [kind of crisis]. So, the capacity we have right now is outstanding given the challenge we’re facing right now.” That turned out not to be true.

On March 2, when New York state registered its first official coronavirus case, de Blasio and Gov. Andrew Cuomo had a rare joint news conference to reassure New Yorkers. Cuomo said, “We should relax, because that’s what’s dictated by the reality of the situation.”

He added: “Excuse our arrogance as New Yorkers — I speak for the mayor also on this one — we think we have the best health care system on the planet right here in New York. So, when you’re saying, what happened in other countries vs. what happened here, we don’t even think it’s going to be as bad as it was in other countries.”

On March 3, de Blasio said, “Occasional contact, glancing contact, temporary contact does not, from everything we know about coronavirus, lead to transmission.” Untrue.

On March 8, de Blasio said, “Certainly, on most surfaces like metal, plastic — you know, a desk, a kitchen counter, a subway pole, it’s only a matter of minutes before the disease dies, the virus dies in the open air.”

On March 9, he said, “It’s not people in the stadium, it’s not people in the big open area or a conference and all” who need to worry about infection. Wrong.

As late as March 11, when the country was coalescing around the need for social distancing, de Blasio said, “If you’re not sick, then you should be going about your life.”

On March 15, both Cuomo and de Blasio were defending the decision to keep schools open, as were we — before a weekend when both changed their minds.

As late as early April, de Blasio claimed that it was “only in the last really 48 hours or so do they feel they’ve seen evidence around the world ... that this disease can be spread by asymptomatic people.” In fact, that realization had set in weeks before.

Remember today so we learn tomorrow.