WASHINGTON — Officials say a fire broke out at a building near the Smithsonian’s National Museum of Natural History in Washington, emitting a plume of black smoke and closing area streets.

Smithsonian spokeswoman Linda St. Thomas says a building detached from the museum that contains the facility’s cooling tower caught fire early Monday. She says it appears the fire started while a contractor was working in the mechanical building.

No smoke entered the main building, where millions of artifacts and specimens are housed. The museum opened to visitors Monday shortly after its regular opening of 10 a.m.

D.C. Deputy Fire Chief Ken Crosswhite says the fire did not pose a risk to the museum. No injuries were reported.