Local artists and the Chicago Rain Forest Action Network posted warning signs over many locations on the south side including this one on Morgan St near 32nd Place.
We found this information at the Just Seeds Blog:
RAN Chicago teamed up with local artists to raise public attention to the Fisk and Crawford coal-powered plants on Chicago's near south side that have been poisoning the air for decades. Both Plants are located in highly populated neighborhoods - primarily Latino neighborhoods - and have operated with outdated equipment and safety standards that has made Chicago one of the worst cities for air quality in the US. Exposure to these plants has led to an average of 40 deaths a year and high rates of asthma and other upper respiratory ailments. The kicker is that these plants do not even benefit Chicago residents. Most of the power produced is sold on the open grid to Ohio and Pennsylvania while community residents (not to mention the ozone layer) suffers, while company execs get rich.
Local groups - LVEJO (Little Village Environmental Justice Organization), PERRO (Pilsen Environmental Rights and Reform Organization), RAN Chicago, and others are calling for the plants to be closed and for the end of burning fossil fuels as an energy source.