Pentagon places staff under emergency lockdown following ‘hazardous materials incident’
Pentagon spokesperson Sean Parnell confirmed in a statement that the building’s security systems detected an air quality issue, prompting preventive measures while the situation is assessed.

Aerial view of the Pentagon in Washington, D.C.
A section of the Pentagon was closed on Thursday, and personnel inside were placed under lockdown as a precautionary measure after a hazardous materials incident was reported at the headquarters of the Department of Defense.
The Arlington County Fire Department reported on X that it had units deployed at the Pentagon, "including our Hazardous Materials Team", during what it described as a "hazardous materials incident."
Containment and response teams deployed
Pentagon spokesperson Sean Parnell, confirmed in a statement that the building’s security systems detected an air quality issue, prompting preventive measures while the situation is assessed.
"The Department is executing standard protection protocols, including a shelter-in-place order for the affected area," Parnell said. He added that response teams are already on site and ready to provide support to those remaining in the building.