Pentagon locked down, some floors evacuated due to 鈥榟azardous materials incident鈥�
(CNN) — The Pentagon was locked down and partially evacuated on Thursday due to a false alarm by a hazardous materials sensor, two sources familiar told CNN.
Multiple floors and corridors inside the building had been locked down and others were evacuated due to a 鈥渉azardous materials incident,鈥� three sources familiar and the local fire department said earlier on Thursday.
As of 12:30pm the lockdown had not been lifted, one of the sources said.
The evacuation was triggered when a Pentagon sensor system detected the possible presence of anthrax, according to first responder radio traffic and a source familiar with the incident. But the sensor system was malfunctioning, one of the sources familiar said, causing the false alarm.
Pentagon spokesman Sean Parnell said that systems within the Pentagon had 鈥渄etected an air quality issue necessitating precautionary measures until we determine its significance.鈥�
鈥淭he Department is executing standard protection protocols, including a shelter-in-place order for the affected area,鈥� Parnell said. 鈥淩esponse teams are in place and ready to support building occupants.鈥�
Internal guidance sent by the Pentagon鈥檚 security team said an 鈥渁ir quality issue鈥� had been detected and additional testing was needed.
鈥淭his additional testing could take one to two hours,鈥� the message said. 鈥淩esponse teams are in place and ready to support building occupants if necessary. You may observe response personnel from multiple agencies and precautionary measures taking place in the center courtyard. Please do not interpret these activities.鈥�
Facilities such as the Pentagon might employ 鈥渃ontinuous air monitoring sampling,鈥� where systems processing large volumes of air look 鈥渇or the presence of [anthrax] spores,鈥� said Jake Jordan, who oversees biosecurity programs for the Nuclear Threat Initiative nonprofit.
While responding hazmat teams may be capable of rapid on-site testing, pathogens such as anthrax require specialized handling for confirmation laboratory tests.
The Arlington County Fire Department sent units to assist the Pentagon Force Protection Agency鈥檚 hazardous materials response team, according to fire department spokesperson Capt. Jamie Jill.
A post on social media from the Arlington Fire & EMS said Arlington County Fire Department Hazardous Materials Team were operating at the Pentagon 鈥渄uring a hazardous materials incident.鈥�
Floors two through five in corridors four through seven of the sprawling Pentagon complex were locked down, two of the sources said. Floors two through five are the above-ground floors of the Pentagon; there are nine corridors total in the building. Offices within the impacted area include the Navy鈥檚 main public affairs office and the Secretary of the Army鈥檚 office.
The third source told CNN that police in the building wore gas masks and full chemical protective gear.
Hayley Severance, who was a former senior advisor to the Defense Department on biological threat reduction before joining the Nuclear Threat Initiative, told CNN that 鈥渢here is a history of 鈥� some false alarms鈥� with anthrax detection, but ultimately 鈥渋t鈥檚 really good that they鈥檙e taking these seriously, because 鈥� it deserves this type of rapid precautionary response.鈥�
This story has been updated with additional reporting.
Davis Winkie鈥檚 work at CNN is supported by a partnership between and Journalism Funding Partners (JFP). CNN retains full editorial control of the reporting.
The-CNN-Wire
™ & © 2026 Cable 海角社区app Network, Inc., a Warner Bros. Discovery Company. All rights reserved.
