The United States' known death toll from COVID-19 will surpass the number of dead from the 1918-19 flu pandemic within the next day or two, according to the side-by-side numbers — though a direct comparison between the raw numbers doesn’t give the whole story, medical experts and statisticians say.

What is clear is that the sheer numbers, given the modern-day tools that combat such illnesses, are a heavy burden. COVID-related U.S. deaths as of Sunday night are at 673,763, according to Johns Hopkins University data.

That’s just over 1,200 fewer than died in the 1918-19 flu pandemic, which took an estimated 675,000 lives in the U.S. Before this, that flu pandemic was the most lethal since the United States was formed. With an 1,800-per-day death average, the number who’ve died of COVID-19 could surpass the previous scourge by Monday.

There are differences between the two scenarios. In 1918, the U.S. population was just over 100 million, whereas it’s 330 million today, as The Washington Post points out. That makes our death rate one in 500 Americans as opposed to the 1918 toll of one in 150.

Globally, the number is 4.7 million dead so far, which is much lower than the worldwide 50 million who died in 1918 and 1919 in the flu pandemic, as Fortune noted. But unlike the two-year period that the flu ravaged humanity’s ranks, COVID-19 is not even close to quitting.

“The fact that deaths surged at the end of 2020, nine months after the pandemic reached the United States, with the highest daily death tolls in early January 2021, is perhaps the most discouraging comparison to the historical record,” Virginia Tech historian E. Thomas Ewing told The Washington Post. “We ignored the lessons of 1918, and then we disregarded warnings issued in the first months of this pandemic. We will never know how many lives could have been saved if we had taken this threat more seriously.”