Firefighters were responding to a hazardous materials incident at the Pentagon on Thursday, according to Arlington County Fire and Rescue officials. The building was partially evacuated and under lockdown, with emergency responders wearing full gas masks and chemical protection suits, CNN reported, citing unnamed sources.
Pentagon spokesman Sean Parnell said in an email that “the Pentagon has sophisticated systems to ensure the safety of the building and its occupants. Those systems have detected an air quality issue necessitating precautionary measures until we determine its significance.”
He added that “the Department is executing standard protection protocols, including a shelter-in-place order for the affected area. Response teams are in place and ready to support building occupants.”
According to CNN, floors two through five were locked down, along with some corridors.
The Pentagon, the five-sided headquarters of the U.S. Department of Defense, was targeted during the September 11, 2001 attacks and remains one of the world’s largest office buildings.