Pentagon evacuates due to hazardous materials incident, later deemed false alarm

Several floors and corridors at the Pentagon were closed and people evacuated from other areas on Thursday due to a "hazardous materials incident." Pentagon spokesman Sean Parnell confirmed that the building's systems detected an air quality problem requiring precautionary measures until its severity could be determined. "The Department is executing standard protection protocols, including issuing a shelter-in-place order for the affected zone," Parnell said. "Response teams are on site and are ready to provide support to those in the building."

The Pentagon Force Protection Agency's hazardous materials response team was on the scene, along with the Arlington County Fire Department's hazardous materials unit. In a social media post, Arlington Fire & EMS stated that their hazardous materials team was working at the Pentagon during a "hazardous materials incident."

A message from the Pentagon security team indicated that an "air quality issue" had been detected and additional testing was needed. "These additional tests may take one to two hours. Response teams are on site and ready to assist building occupants if necessary. You may see personnel from various agencies and security measures being taken in the central courtyard. Please do not draw conclusions from these actions," the message said.

Two of three sources reported that floors two through five in the vast Pentagon complex were closed. A third source told CNN that police in the building were wearing gas masks and full chemical protective gear.

Later, CNN reported citing sources that the hazardous materials incident was a false alarm. The evacuation order from multiple floors of the U.S. Defense Department headquarters was given due to a mistaken alert.