When Hillary Clinton was running against Donald Trump in 2016, she boiled down concerns about his temperament to a central question: “Imagine Donald Trump sitting in the Situation Room, making life-or-death decisions on behalf of the United States,” she said. The attack was centered on national security, but the argument went beyond the role of commander in chief to broader questions about Trump’s ability to handle any number of potential crises. How would he react to a public health emergency? How would he deal with a natural disaster?

We now have an answer to this question as the scope of devastation from Hurricane Maria becomes more clear. What we have learned is that there are life-and-death consequences to putting someone like Donald Trump in command of the federal government. The profound failure of leadership and management that Trump’s critics feared has actually happened, and we are just now learning the scale of that disaster.

Puerto Ricans were still recovering from Hurricane Irma when Maria made landfall last autumn. The storm devastated the island, destroying homes and crippling vital infrastructure. The crisis that ensued demanded an immediate and robust response from the federal government. But the response was sluggish, even as early reports made clear that this was a serious tragedy in the making. The White House made few preparations in the lead-up to the storm, and it was weeks before the Federal Emergency Management Agency committed its full resources to the island. During that time, clean water was scarce, food was hard to find, and hospitals struggled to care for patients, some with serious injuries and illnesses. Most of Puerto Rico lacked electricity for months, and medical supplies were few and far between. When FEMA did eventually act, it dropped the ball. To deliver 30 million meals, the agency contracted with an Atlanta-based wedding caterer with no experience in emergency management. By the time the company’s contract was terminated, it had delivered just 50,000 of those meals.

The impact of those missteps wasn’t immediately clear. According to the government, only 64 people died in the disaster, compared to more than 1,800 who are estimated to have died in Hurricane Katrina. Trump noted that difference when he visited the island. “Every death is a horror,” said Trump, “but if you look at a real catastrophe like Katrina, and you look at the tremendous—hundreds and hundreds and hundreds of people that died, and you look at what happened here, with really a storm that was just totally overpowering, nobody’s ever seen anything like this.” He was congratulating himself, and even took to Twitter to complain of unfair treatment from those who faulted the administration’s response: “Nobody could have done what I’ve done for #PuertoRico with so little appreciation. So much work!”

We now know this initial death toll was likely wrong by many orders of magnitude. Tracking deaths is always difficult in the wake of such a serious disaster, but recent research makes it clear that the federal government grossly undercounted the number of people who died due to this hurricane. After a review of mortality data, both the New York Times and the Center for Investigative Journalism estimated more than 1,000 deaths from the hurricane and its aftermath. A new Harvard study, released on Tuesday and published in the New England Journal of Medicine, estimated that at least 4,465 people died as a result of Hurricane Maria, which would make it the deadliest natural disaster to strike the United States since 1900, when a powerful hurricane devastated Galveston, Texas, and surrounding areas, killing at least 8,000 people. The researchers, who surveyed thousands of randomly selected homes in Puerto Rico, asked residents about deaths and extrapolated from the results, attributing many of the deaths to hospital disruptions and loss of basic utility services.

A faster, stronger response would have prevented some of those deaths. Even if the White House was unprepared when the storm initially hit, much of the aftermath could have been averted if President Trump had focused his administration on the disaster and brought the weight of the federal government to bear on the unfolding tragedy. Instead, Trump sent every signal that he simply didn’t care. He downplayed the devastation to Puerto Rico and blamed Puerto Ricans for not doing more to repair the damage. He went after the mayor of San Juan, who had criticized the government’s response. He didn’t use his Twitter account to publicize relief efforts or generally encourage Americans to help. What he did do during that time, however, was campaign for political allies and start a feud with black football players.

Puerto Rico is part of the United States, Puerto Ricans are Americans citizens, and as president, Donald Trump had a responsibility to assist them as they battled disaster. He didn’t, and the result was suffering and death on a massive scale.

The extraordinary scandals of the Trump administration—including the president’s public effort to shield himself and his associates from wrongdoing—are important. But they should not blind us to the very real weight of his more ordinary transgressions. Donald Trump failed Puerto Rico, and no one should forget it.