A portion of the Pentagon was evacuated Tuesday following the detection of air quality issues, according to CNN. Department of Defense spokesperson Sean Parnell stated that systems flagged problems with air quality within the building. Firefighters, equipped with protective gear and gas masks, are currently on the scene investigating the cause. The incident is being described as involving “hazardous materials,” though the specific nature of the substance remains unclear. Authorities have not yet disclosed the extent of the evacuation or potential health risks. An investigation is underway to determine the source of the air quality concerns and ensure the safety of personnel. No injuries have been reported at this time.