The Arlington County Fire Department (ACFD) posted on X at 10:41 a.m. local time that it was responding to the incident.
“ACFD units, including our Hazardous Materials Team, are currently operating at the Pentagon,” the department wrote, noting that they were working in conjunction with the Pentagon Force Protection Agency Hazmat Team in response to a “hazardous materials incident.”
Two sources familiar with the incident told CNN around noon that the lockdown and evacuation were due to a false alarm. The Pentagon and ACFD have not publicly confirmed whether this is the case.
Sources familiar with the matter had previously told the outlet that multiple floors and corridors at the Pentagon had been locked down, including floors two through five in the fourth through the seventh corridors. Others were being evacuated and police in the building were wearing full chemical protective gear and gas masks, sources told the outlet.

