The Pentagon has gone into lockdown due to an air quality issue, with response teams being mobilized to assess the situation.

The Pentagon was placed on lockdown Tuesday morning due to an air quality issue, according to spokesperson Sean Parnell. The building's systems detected a problem that requires precautionary measures, including a shelter-in-place order for the affected area. Response teams are prepared to assist the building's occupants. The Arlington Fire Department confirmed that its hazardous materials team is responding to an ongoing incident at the Pentagon. Some individuals have been evacuated, and police were observed wearing protective gear, including gas masks. The Pentagon, located near the Potomac River, is the headquarters of the Department of Defense and houses approximately 27,000 employees, including military and civilian personnel. This is a developing story, and updates will be provided as information becomes available.