The Pentagon returned to “normal operations” hours after an “air quality issue” prompted a shelter-in-place order.

“Earlier this morning, Pentagon occupants were notified of a potential air quality issue, prompting immediate precautionary safety measures and evaluation,” Pentagon chief spokesman Sean Parnell said in a statement. “Subsequent testing confirmed no hazard exists, and normal operations have resumed.”

“We express our sincere appreciation to the first responders for their swift actions to ensure the safety of all personnel,” Parnell said.