The soldiers were staying at the Marriott Marquis Hotel during their mission to the nation's capital when they decided to order a pizza from a nearby establishment using Uber Eats, according to a Department of Defense report shared with The Post and Courier.
When they opened the pizza, they found shards of glass baked into the dough and cheese.
They didn't eat the pizza and no one was injured, according to the report. No other Guardsmen experienced a similar problem.
"The command says that the soldiers are OK, and that this was the only incident to their knowledge," said Capt. Jessica Donnelly, a spokeswoman for the S.C. National Guard.
She said the soldiers were advised to file a police report about the incident. A spokeswoman for the D.C. Metro Police Department said there was no report on file.
Department of Defense personnel have seen an increase in threats, according to the report, but it went on to state that there have been no specific threats made by protesters against soldiers.
The soldiers' names were not mentioned in the Department of Defense report or named by S.C. National Guard officials.
The S.C. National Guard troops returned from their deployment on Tuesday. Gov. Henry McMaster sent nearly 500 soldiers to Washington, D.C., last week to support President Donald Trump.
Trump said he wanted to "dominate" the streets in response to protesters. The demonstrations were sparked by the death of George Floyd, a black man from Minneapolis whose death at the hands of police was captured on video.
Their presence was criticized by protesters and lawmakers, who said the National Guard's deployment to the nation's capital was an excessive show of force. D.C. Mayor Muriel Bowser also spoke out against their presence and the Guardsmen had to move out of their hotel later in the week because of a budgetary issue with the city and the guard.
While they faced little physical confrontation from protesters, two S.C. National Guardsmen were hospitalized after lightning struck near Lafayette Square, where they were providing security near the White House early Friday morning.
Editor's note: This article has been updated to reflect clarified information from the S.C. National Guard and additional context from the Department of Defense report.