Chicago's Coal Plants To Close: Mayor's Ultimatum Leads To Environmentalists' Win (VIDEO)

Chicago environmentalists won a hard-fought victory late Tuesday as the city's two coal power plants announced that they will close -- one of them by the end of the year.

The Chicago Sun-Times reports that Midwest Generation has agreed to close its two coal fire plants. The Fisk generating station, in the city's Pilsen neighborhood, is slated to close by Dec. 31, while the Crawford plant in Little Village will close by the end of 2014.

(Scroll down to watch a report on the plants' closure.)

A mayoral aide, who asked to remain anonymous, told the Sun-Times that the company "could decide to significantly reduce emissions, but energy prices are bottoming out and the cost of retrofitting the plants would be heavy. They don’t want to make that type of investment. At the end of the day, this is an economic decision."

The aide further noted that, because the agreement was reached without having to deal with a City Council ordinance, a costly court challenge will be avoided. Midwest Generation officials declined to comment on their decision to the Sun-Times.

The Chicago Clean Power Coalition, which had backed the ordinance and earlier this month urged for the mayor to "finish the work" of closing the plants, said of the decision that "Chicagoans have finally won the right to breathe clean air." The group estimates that pollution from the two plants cause 42 premature deaths, 66 heart attacks and 720 asthma attacks annually.

"Today’s victory demonstrates that people shouldn’t have to tolerate toxic polluters in their backyard," Rosalie Mancera of Pilsen Alliance said in a statement.

Environmental groups including the Sierra Club and others will, as part of the agreement, drop their lawsuit against Midwest Generation, the Chicago Tribune reports.

The two plants have been operating in Chicago for over a century and were identified last month by the U.S. Environmental Protection Agency as the city's two biggest industrial sources of pollution. Their emissions have long violated the federal Clean Air Act of 1977, but they were grandfathered in under that law due to the plants' age.

WATCH a report on the newly announced closure of Chicago's coal plants: