Virginia emergency crews deployed to the Pentagon on Thursday morning for what authorities described as a “hazardous materials incident.”

Subscribe to read this story ad-free

Get unlimited access to ad-free articles and exclusive content.

Pentagon spokesman Sean Parnell confirmed that “sophisticated systems” had “detected an air quality issue necessitating precautionary measures until we determine its significance.”

“The Department is executing standard protection protocols, including a shelter-in-place order for the affected area,” Parnell added, referring to the Defense Department. “Response teams are in place and ready to support building occupants.”

In a post on X, the Arlington County Fire Department said emergency units, including its hazardous materials team, were “operating at the Pentagon in support of PFPA’s Hazmat Team during a hazardous materials incident.”