President Joe Biden is ordering all flags on federal property to be flown at half staff in honor of the estimated 500,000 Americans who have died from the coronavirus.

According to Johns Hopkins University, the U.S. surpassed 500,000 coronavirus deaths Monday afternoon as the final week of February began, a slower approach to that grim milestone than was forecast by the Atlanta-based Centers for Disease Control and Prevention last month. As of 4:45 p.m. ET, Johns Hopkins reported 500,071 deaths.

On Jan. 20, the CDC released a national forecast that predicted the nation’s coronavirus death toll to have reached up to 508,000 deaths by the week ending Feb. 13.

A year into the pandemic, the running total of lives lost was roughly the population of Kansas City, Missouri, and just shy of the size of Atlanta. The figure compiled by Johns Hopkins University surpasses the number of people who died in 2019 of chronic lower respiratory diseases, stroke, Alzheimer’s, flu and pneumonia combined.

“It’s nothing like we have ever been through in the last 102 years, since the 1918 influenza pandemic,” the nation’s top infectious disease expert, Dr. Anthony Fauci, said on CNN’s “State of the Union.”

The U.S. virus death toll reached 400,000 on Jan. 19 in the waning hours in office for President Donald Trump.

The nation passed the milestone Monday afternoon. Biden will mark the U.S. crossing 500,000 lives lost from COVID-19 with a moment of silence and candle lighting ceremony at the White House.

Biden will deliver remarks at sunset to honor the dead, the White House said. He’s expected to be joined by first lady Jill Biden and Vice President Kamala Harris and her husband, Doug Emhoff.

Experts warn that over 100,000 more deaths are likely in the next few months, despite a massive campaign to vaccinate people. Meanwhile, the nation’s trauma continues to accrue in a way unparalleled in recent American life, said Donna Schuurman of the Dougy Center for Grieving Children & Families in Portland, Oregon.

“In a way, we’re all grieving,” said Schuurman, who has counseled the families of those killed in terrorist attacks, natural disasters and school shootings.

Globally, more than 111 million cases of the coronavirus have been recorded, according to Johns Hopkins. The U.S. continues to lead the world in cases — 28.1 million — and deaths.

In recent weeks, virus deaths have fallen from more than 4,000 reported on some days in January to an average of fewer than 1,900 per day.

Still, at almost half a million, the toll recorded by Johns Hopkins University is already greater than the population of Miami or Kansas City, Missouri. It is roughly equal to the number of Americans killed in World War II, the Korean War and the Vietnam War combined. It is akin to a 9/11 every day for nearly six months.

The first known deaths from the virus in the U.S. happened in early February 2020, both of them in Santa Clara County, California. It took four months to reach the first 100,000 dead. The toll hit 200,000 deaths in September and 300,000 in December. Then it took just over a month to go from 300,000 to 400,000 and about two months to climb from 400,000 to the brink of 500,000.

The seven-day rolling average of new infections was well above 200,000 for much of December and went to roughly 250,000 in January, according to data kept by Johns Hopkins, as the pandemic came roaring back after it had been tamed in some places during the summer.

That average dropped below 100,000 on Feb. 12 for the first time since Nov. 4. It stayed below 100,000 on Feb. 13.

Last week, the CDC said life expectancy in the U.S. dropped one year during the first half of 2020 as the coronavirus pandemic caused its first wave of deaths.

Minorities suffered the biggest impact, with Black Americans losing nearly three years and Hispanics nearly two years.

“This is a huge decline,” said Robert Anderson, who oversees the numbers for the CDC. “You have to go back to World War II, the 1940s, to find a decline like this.”

This is the first time the CDC has reported on life expectancy from early, partial records; more death certificates from that period may yet come in. It’s already known that 2020 was the deadliest year in U.S. history, with deaths topping 3 million for the first time.

Life expectancy is how long a baby born today can expect to live, on average. In the first half of last year, that was 77.8 years for Americans overall, down one year from 78.8 in 2019. For males, it was 75.1 years and for females 80.5 years.

“The focus really needs to be broad spread of getting every American adequate care,” said Dr. Otis Brawley, a cancer specialist and public health professor at Johns Hopkins University. “And health care needs to be defined as prevention as well as treatment.”

Overall, the drop in life expectancy is more evidence of “our mishandling of the pandemic,” Brawley said. “We have been devastated by the coronavirus more so than any other country. We are 4% of the world’s population, more than 20% of the world’s coronavirus deaths,” he said.

Not enough use of masks, early reliance on drugs such as hydroxychloroquine, “which turned out to be worthless,” and other missteps meant many Americans died needlessly, Brawley said.

“Going forward, we need to practice the very basics” such as hand washing, physical distancing and vaccinating as soon as possible to get prevention back on track, he said.

The Associated Press and Rich Barak of The Atlanta Journal-Constitution contributed to this report.