米国防総省、「有害物質」の懸念で閉鎖　一部職員が退避の騒ぎに：朝日新聞

Pentagon lockdown and evacuation was due to a false alarm, sources say

Pentagon lockdown in floors 2-5, corridors 4-7 resulted from false air quality alarm; no hazmat incident detected. Exposes calibration challenges in critical infrastructure detection systems; false positives mobilize costly emergency response protocols.