The sentinels at the Tomb of the Unknown Soldier stand guard 24 hours a day, every day, to honor Americans who died in service of their country.
And a photo taken during Thursday's round of severe weather captured the dedication and persistence that guards have upheld since 1937.
As thousands of people ducked inside to avoid blinding rain and a tornado warning around Washington, D.C., U.S. Army Sgt. Maryam Treece snapped photos of a soldier carrying on with planting flags.
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"Some had to be ordered to stand down from planting flags, still determined to continue to honor the fallen," 3rd U.S. Infantry Regiment, also known as The Old Guard, posted on Facebook. "America's regiment endured."
Flags In is a Memorial Day weekend tradition when soldiers place more than 245,000 American flags at Arlington National Cemetery graves, the Old Guard says.
Treece's photos have been shared more than 130,000 times on Facebook alone.
"Humans have their limits, but The Old Guard has yet to meet theirs," the Facebook post said.
Indeed, the Old Guard has stood firm while being battered by the elements, including a 2016 blizzard and through Hurricane Sandy in 2012.