A flash fire broke out in the ductwork of the State Department during construction repairs, injuring four people, reports AP.
NBC Washington reports that local fire and EMS crews were called to the State Department on Saturday morning after the fire broke out around 11 a.m. while work crews were performing maintenance in the building.
The fire was extinguished but four construction workers were taken to Washington Hospital Center with injuries. According to CNN, one worker was in a "life-threatening condition" and the other two people were in serious but non-life threatening condition.
The fourth person fell from a ladder and hurt his knee, authorities said. NBC reports that other burned workers were treated at the scene and not hospitalized.
There were few State Department employees in the building on Saturday because of the Thanksgiving holiday.
Maintenance crews were working on the eighth floor of the building, which is home to the State Department's Diplomatic Reception Rooms, where visiting heads of state are officially entertained, reports The Hill.
The cause of the fire is unknown but authorities said it is not suspicious.