Multiple Pentagon floors locked down, evacuated due to 'hazardous materials incident'

The Pentagon was locked down and partially evacuated on Thursday due to what officials say was a false alarm by a hazardous materials sensor. The sensor system detected the possible presence of anthrax, but the system was malfunctioning, one source said, causing the false alarm.

Multiple floors and corridors inside the building had been locked down and others were evacuated due to the “hazardous materials incident.” As of 12:30pm the lockdown had not been lifted.

Pentagon spokesman Sean Parnell confirmed that systems within the Pentagon had detected an air quality issue necessitating precautionary measures. “The Department is executing standard protection protocols, including a shelter-in-place order for the affected area,” Parnell said.

The Pentagon Force Protection Agency’s hazardous materials response team responded with assistance from the Arlington County Fire Department. Police in the building wore gas masks and full chemical protective gear.

Floors two through five in corridors four through seven of the sprawling complex were locked down. These above-ground floors contain offices including the Navy’s main public affairs office and the Secretary of the Army’s office.

Internal guidance from the Pentagon’s security team said additional testing was needed and could take one to two hours. Response teams were in place and ready to support building occupants if necessary. Personnel were advised not to interpret response activities from multiple agencies taking place in the center courtyard.