WASHINGTON (AP) — Authorities say three maintenance workers were seriously injured after a fire broke out at the State Department headquarters in Washington.

D.C. Fire and EMS spokesman Lon Walls said the fire broke out at around 11 a.m. Saturday in the ductwork on the 7th floor. Workers were able to put out the fire before firefighters arrived, but three people suffered burns.

Walls said one person suffered life-threatening injuries and two others had serious but non-life-threatening injuries. All three were taken to Washington Hospital Center.

State department spokeswoman Victoria Nuland said the fire broke out during routine maintenance to a mechanical area of the building. She said the building was briefly evacuated and then reopened.