The Boston Fire Department reports that firefighters who responded to an alarm at the Veolia steam plant at 165 Kneeland St. around 7:30 p.m. found fire on multiple floors in the eight-story plant.
The fire, which went to two alarms, caused no injuries and is now under investigation, the department says.
Steam from the plant travels through pipes under downtown streets to heat older buildings.
City records show the plant first came online in 1928.
It's currently assessed at $10.8 million, down from $11.5 million in 2019. In a tax decision in September of that year, the Supreme Judicial Court ruled that the plant, smaller plants on Scotia Street and in Kendall Square in Cambridge and all the pipes that connect them to customer buildings are part of a "great integral machine," and so exempt from certain taxes under state law and rulings dating to the 1860s.