Leading disease forecasters, whose research the White House used to conclude 100,000 to 240,000 people will die nationwide from the coronavirus, were mystified when they saw the administration’s projection this week.

The experts said they don’t challenge the numbers’ validity but said they don’t know how the White House arrived at them.

White House officials have refused to explain how they generated the figure — a death toll bigger than the United States suffered in the Vietnam War or the 9/11 terrorist attacks. They have not provided the underlying data so others can assess its reliability or provided long-term strategies to lower that death count.

Some of President Trump’s top advisers have expressed doubts about the estimate, according to three White House officials who spoke on the condition of anonymity because they were not authorized to speak publicly. There have been fierce debates inside the White House about its accuracy.