Air quality groups in Pittsburgh are fired up over a string of fires — including a recent incident on June 13 — at U.S. Steel’s Clairton Coke Works, located about 30 minutes south of Oakland.

Activists with Pittsburgh’s Breathe Project met outside the U.S. Steel Tower Tuesday afternoon and declared “enough is enough,” calling for an independent audit of U.S. Steel’s troubled Clairton Coke Works plant.

An electrical fire occurred at U.S. Steel’s Clairton Coke Works plant early Monday morning rendering desulfurization, or pollution control, systems inoperational, according to the Allegheny County Health Department.